diff --git a/README.md b/README.md
index f0d9a46..538d93b 100644
--- a/README.md
+++ b/README.md
@@ -51,19 +51,20 @@ export default function MyPage() {
 
 ## Props
 
-| Property          | Description                                                                                                                                                                                                                                                                                             |
-| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| `allowedHtmlTags` | `string[]` = ['b', 'strong', 'i', 'em', 'sub', 'sup']<br />Optional list of HTML tags allowed within the clues. Use `[]` to prevent all HTML tags. Defaults to `['b', 'strong', 'i', 'em', 'sub', 'sup']`.                                                                                           |
-| `cellMatcher`     | `RegExp` = '/[A-Z]/'<br />Optional regular expression to match against entered cell characters. Defaults to `/[A-Z]/`.                                                                                                                                                                                  |
-| `className`       | `string`<br />Optional string to apply a space-delimited list of class names.                                                                                                                                                                                                                           |
-| `data`            | `GuardianCrossword`<br />Required object that contains crossword clues, solutions and other information needed to draw the grid. See [crossword data](#crossword-data) below for more information.                                                                                                      |
-| `id`              | `string`<br />Required string to uniquely identify the crossword.                                                                                                                                                                                                                                       |
-| `loadGrid`        | `GuessGrid \| undefined`<br />Optional object to override storage mechanism. Called when the component is initialized with the ID of the crossword. Should return an array-based representation of the crossword grid. See [guess grid](#guess-grid) below for more information.                        |
-| `onCellChange`    | `(cellChange: CellChange) => void \| undefined`<br />Optional function. Called after a grid cell has changed its guess. The object contains the properties `pos`, `guess` and `previousGuess`.                                                                                                          |
-| `onCellFocus`     | `(cellFocus: CellFocus) => void \| undefined`<br />Optional function. Called after the focus switches to a new cell. The object returned contains the properties `pos` and `clueId`.                                                                                                                    |
-| `saveGrid`        | `(value: GuessGrid \| ((val: GuessGrid) => GuessGrid)) => void \| undefined`<br />Optional function to override storage mechanism. Called after the grid has changed with the ID of the crossword and array-based representation of the grid. See [guess grid](#guess-grid) below for more information. |
-| `stickyClue`      | `'always' \| 'never' \| 'auto'` = 'auto'<br />Optional value to define when to show the sticky clue above the grid. Defaults to `'auto'` (shown on `xs` and `sm` breakpoints).                                                                                                                          |
-| `theme`           | `'red' \| 'pink' \| 'purple' \| 'deepPurple' \| 'indigo' \| 'blue' \| 'lightBlue' \| 'cyan' \| 'teal' \| 'green' \| 'deepOrange' \| 'blueGrey'` = 'blue'<br />Optional value to override the main colour applied to the highlighted cells and clues. Defaults to `'blue'`.                              |
+| Property                | Description                                                                                                                                                                                                                                                                                             |
+| ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `allowedHtmlTags`       | `string[]` = ['b', 'strong', 'i', 'em', 'sub', 'sup']<br />Optional list of HTML tags allowed within the clues. Use `[]` to prevent all HTML tags. Defaults to `['b', 'strong', 'i', 'em', 'sub', 'sup']`.                                                                                              |
+| `allowMissingSolutions` | `boolean` = false<br />Optional flag to relax grid validation. This will allow the `data` prop to have missing or incomplete solutions in its entries.                                                                                                                                                  |
+| `cellMatcher`           | `RegExp` = '/[A-Z]/'<br />Optional regular expression to match against entered cell characters. Defaults to `/[A-Z]/`.                                                                                                                                                                                  |
+| `className`             | `string`<br />Optional string to apply a space-delimited list of class names.                                                                                                                                                                                                                           |
+| `data`                  | `GuardianCrossword`<br />Required object that contains crossword clues, solutions and other information needed to draw the grid. See [crossword data](#crossword-data) below for more information.                                                                                                      |
+| `id`                    | `string`<br />Required string to uniquely identify the crossword.                                                                                                                                                                                                                                       |
+| `loadGrid`              | `GuessGrid \| undefined`<br />Optional object to override storage mechanism. Called when the component is initialized with the ID of the crossword. Should return an array-based representation of the crossword grid. See [guess grid](#guess-grid) below for more information.                        |
+| `onCellChange`          | `(cellChange: CellChange) => void \| undefined`<br />Optional function. Called after a grid cell has changed its guess. The object contains the properties `pos`, `guess` and `previousGuess`.                                                                                                          |
+| `onCellFocus`           | `(cellFocus: CellFocus) => void \| undefined`<br />Optional function. Called after the focus switches to a new cell. The object returned contains the properties `pos` and `clueId`.                                                                                                                    |
+| `saveGrid`              | `(value: GuessGrid \| ((val: GuessGrid) => GuessGrid)) => void \| undefined`<br />Optional function to override storage mechanism. Called after the grid has changed with the ID of the crossword and array-based representation of the grid. See [guess grid](#guess-grid) below for more information. |
+| `stickyClue`            | `'always' \| 'never' \| 'auto'` = 'auto'<br />Optional value to define when to show the sticky clue above the grid. Defaults to `'auto'` (shown on `xs` and `sm` breakpoints).                                                                                                                          |
+| `theme`                 | `'red' \| 'pink' \| 'purple' \| 'deepPurple' \| 'indigo' \| 'blue' \| 'lightBlue' \| 'cyan' \| 'teal' \| 'green' \| 'deepOrange' \| 'blueGrey'` = 'blue'<br />Optional value to override the main colour applied to the highlighted cells and clues. Defaults to `'blue'`.                              |
 
 For more type information, see [interfaces](./src/interfaces).
 
diff --git a/example/src/App.tsx b/example/src/App.tsx
index df7d9c1..244b736 100644
--- a/example/src/App.tsx
+++ b/example/src/App.tsx
@@ -4,26 +4,27 @@ import * as React from 'react';
 import './App.css';
 import data from './guardian.cryptic.28505';
 
+const ALLOWED_HTML_TAGS = ['b', 'strong', 'i', 'em', 'sub', 'sup'] as const;
+
 // TODO: import from MyCrossword
-const themeColors = [
-  'red',
-  'pink',
-  'purple',
+const THEME_COLORS = [
+  'blue',
+  'blueGrey',
+  'cyan',
+  'deepOrange',
   'deepPurple',
+  'green',
   'indigo',
-  'blue',
   'lightBlue',
-  'cyan',
+  'pink',
+  'purple',
+  'red',
   'teal',
-  'green',
-  'deepOrange',
-  'blueGrey',
 ] as const;
-type Theme = typeof themeColors[number];
+type ThemeColor = typeof THEME_COLORS[number];
 
 export default function App() {
-  const allowedHtmlTags = ['b', 'strong', 'i', 'em', 'sub', 'sup'];
-  const [theme, setTheme] = React.useState<Theme>('blue');
+  const [theme, setTheme] = React.useState<ThemeColor>(THEME_COLORS[0]);
   const [showDefinitions, setShowDefinitions] = React.useState(false);
 
   return (
@@ -52,9 +53,9 @@ export default function App() {
             <select
               id="theme"
               value={theme}
-              onChange={(e) => setTheme(e.target.value as Theme)}
+              onChange={(e) => setTheme(e.target.value as ThemeColor)}
             >
-              {themeColors.map((color) => (
+              {THEME_COLORS.map((color) => (
                 <option key={color} value={color}>
                   {color}
                 </option>
@@ -73,7 +74,9 @@ export default function App() {
         </div>
         <MyCrossword
           allowedHtmlTags={
-            showDefinitions ? [...allowedHtmlTags, 'u'] : allowedHtmlTags
+            showDefinitions
+              ? [...ALLOWED_HTML_TAGS, 'u']
+              : [...ALLOWED_HTML_TAGS]
           }
           id={data.id}
           data={data}
diff --git a/example/src/guardian.prize.25220.ts b/example/src/guardian.prize.25220.ts
index 428aa60..3c9ba7c 100644
--- a/example/src/guardian.prize.25220.ts
+++ b/example/src/guardian.prize.25220.ts
@@ -463,8 +463,8 @@ const data: GuardianCrossword = {
     name: 'Araucaria',
     webUrl: 'https://www.theguardian.com/profile/araucaria',
   },
-  date: 123,
-  dateSolutionAvailable: 123,
+  date: 1295049600000,
+  dateSolutionAvailable: 1295049600000,
   solutionAvailable: true,
 };
 
diff --git a/example/src/incomplete.cryptic.ts b/example/src/incomplete.cryptic.ts
new file mode 100644
index 0000000..d53e377
--- /dev/null
+++ b/example/src/incomplete.cryptic.ts
@@ -0,0 +1,358 @@
+import type { GuardianCrossword } from 'mycrossword';
+
+const data: GuardianCrossword = {
+  id: 'test',
+  number: 0,
+  name: 'Grid with missing solutions',
+  creator: {
+    name: 'Raider',
+    webUrl: '',
+  },
+  date: 1709718868633,
+  solutionAvailable: true,
+  dimensions: {
+    rows: 15,
+    cols: 15,
+  },
+  crosswordType: 'cryptic',
+  entries: [
+    {
+      id: '6-across',
+      number: 6,
+      humanNumber: '6',
+      direction: 'across',
+      clue: '(13)',
+      length: 13,
+      group: ['6-across'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 1,
+        y: 1,
+      },
+    },
+    {
+      id: '8-across',
+      number: 8,
+      humanNumber: '8',
+      direction: 'across',
+      clue: '(3,3)',
+      length: 6,
+      group: ['8-across'],
+      solution: 'ONETWO',
+      separatorLocations: {
+        ',': [3],
+      },
+      position: {
+        x: 0,
+        y: 3,
+      },
+    },
+    {
+      id: '9-across',
+      number: 9,
+      humanNumber: '9',
+      direction: 'across',
+      clue: 'More than one... (7)',
+      length: 7,
+      group: ['9-across'],
+      solution: 'SEVERAL',
+      separatorLocations: {},
+      position: {
+        x: 7,
+        y: 3,
+      },
+    },
+    {
+      id: '10-across',
+      number: 10,
+      humanNumber: '10',
+      direction: 'across',
+      clue: '(15)',
+      length: 15,
+      group: ['10-across'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 0,
+        y: 5,
+      },
+    },
+    {
+      id: '11-across',
+      number: 11,
+      humanNumber: '11, 17',
+      direction: 'across',
+      clue: '(7-5)',
+      length: 7,
+      group: ['11-across', '17-down'],
+      solution: 'BETWEEN',
+      separatorLocations: {
+        '-': [7],
+      },
+      position: {
+        x: 0,
+        y: 7,
+      },
+    },
+    {
+      id: '13-across',
+      number: 13,
+      humanNumber: '13',
+      direction: 'across',
+      clue: '(7)',
+      length: 7,
+      group: ['13-across'],
+      solution: 'ANSWERS',
+      separatorLocations: {},
+      position: {
+        x: 8,
+        y: 7,
+      },
+    },
+    {
+      id: '16-across',
+      number: 16,
+      humanNumber: '16',
+      direction: 'across',
+      clue: '(15)',
+      length: 15,
+      group: ['16-across'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 0,
+        y: 9,
+      },
+    },
+    {
+      id: '19-across',
+      number: 19,
+      humanNumber: '19',
+      direction: 'across',
+      clue: '(7)',
+      length: 7,
+      group: ['19-across'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 1,
+        y: 11,
+      },
+    },
+    {
+      id: '20-across',
+      number: 20,
+      humanNumber: '20',
+      direction: 'across',
+      clue: '(5)',
+      length: 6,
+      group: ['20-across'],
+      solution: 'SHORT',
+      separatorLocations: {},
+      position: {
+        x: 9,
+        y: 11,
+      },
+    },
+    {
+      id: '21-across',
+      number: 21,
+      humanNumber: '21',
+      direction: 'across',
+      clue: '(13)',
+      length: 13,
+      group: ['21-across'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 1,
+        y: 13,
+      },
+    },
+    {
+      id: '1-down',
+      number: 1,
+      humanNumber: '1',
+      direction: 'down',
+      clue: '(6)',
+      length: 6,
+      group: ['1-down'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 3,
+        y: 0,
+      },
+    },
+    {
+      id: '2-down',
+      number: 2,
+      humanNumber: '2',
+      direction: 'down',
+      clue: '(15)',
+      length: 15,
+      group: ['2-down'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 5,
+        y: 0,
+      },
+    },
+    {
+      id: '3-down',
+      number: 3,
+      humanNumber: '3',
+      direction: 'down',
+      clue: '(7)',
+      length: 7,
+      group: ['3-down'],
+      solution: 'MISSING',
+      separatorLocations: {},
+      position: {
+        x: 7,
+        y: 0,
+      },
+    },
+    {
+      id: '4-down',
+      number: 4,
+      humanNumber: '4',
+      direction: 'down',
+      clue: '(6,3,6)',
+      length: 15,
+      group: ['4-down'],
+      solution: 'LOAVESANDFISHES',
+      separatorLocations: {
+        ',': [6, 9],
+      },
+      position: {
+        x: 9,
+        y: 0,
+      },
+    },
+    {
+      id: '5-down',
+      number: 5,
+      humanNumber: '5',
+      direction: 'down',
+      clue: '(8)',
+      length: 8,
+      group: ['5-down'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 11,
+        y: 0,
+      },
+    },
+    {
+      id: '6-down',
+      number: 6,
+      humanNumber: '6',
+      direction: 'down',
+      clue: '(7)',
+      length: 7,
+      group: ['6-down'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 1,
+        y: 1,
+      },
+    },
+    {
+      id: '7-down',
+      number: 7,
+      humanNumber: '7',
+      direction: 'down',
+      clue: '(5)',
+      length: 5,
+      group: ['7-down'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 13,
+        y: 1,
+      },
+    },
+    {
+      id: '12-down',
+      number: 12,
+      humanNumber: '12',
+      direction: 'down',
+      clue: '(8)',
+      length: 8,
+      group: ['12-down'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 3,
+        y: 7,
+      },
+    },
+    {
+      id: '14-down',
+      number: 14,
+      humanNumber: '14',
+      direction: 'down',
+      clue: '(7)',
+      length: 7,
+      group: ['14-down'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 13,
+        y: 7,
+      },
+    },
+    {
+      id: '15-down',
+      number: 15,
+      humanNumber: '15',
+      direction: 'down',
+      clue: '(7)',
+      length: 7,
+      group: ['15-down'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 7,
+        y: 8,
+      },
+    },
+    {
+      id: '17-down',
+      number: 17,
+      humanNumber: '17',
+      direction: 'down',
+      clue: 'See 11a',
+      length: 5,
+      group: ['11-across', '17-down'],
+      solution: 'TIMES',
+      separatorLocations: {},
+      position: {
+        x: 1,
+        y: 9,
+      },
+    },
+    {
+      id: '18-down',
+      number: 18,
+      humanNumber: '18',
+      direction: 'down',
+      clue: '(6)',
+      length: 6,
+      group: ['18-down'],
+      solution: '',
+      separatorLocations: {},
+      position: {
+        x: 11,
+        y: 9,
+      },
+    },
+  ],
+};
+
+export default data;
diff --git a/src/components/Crossword/Crossword.test.tsx b/src/components/Crossword/Crossword.test.tsx
index 9dae20e..028fab1 100644
--- a/src/components/Crossword/Crossword.test.tsx
+++ b/src/components/Crossword/Crossword.test.tsx
@@ -8,12 +8,13 @@ import validData from './../../testData/test.valid.1';
 import { act, fireEvent, render, screen } from './../../utils/rtl';
 import Crossword from './Crossword';
 
-const debounceTime = 1000;
+const DEBOUNCE_TIME = 1000;
 
 test('it renders', () => {
   render(
     <Crossword
       allowedHtmlTags={DEFAULT_HTML_TAGS}
+      allowMissingSolutions={false}
       cellMatcher={DEFAULT_CELL_MATCHER}
       data={validData}
       id="test"
@@ -41,6 +42,7 @@ test('it displays error with invalid data', () => {
   render(
     <Crossword
       allowedHtmlTags={DEFAULT_HTML_TAGS}
+      allowMissingSolutions={false}
       cellMatcher={DEFAULT_CELL_MATCHER}
       data={invalidData}
       id="test"
@@ -74,6 +76,7 @@ test('it displays valid guess grid', () => {
   render(
     <Crossword
       allowedHtmlTags={DEFAULT_HTML_TAGS}
+      allowMissingSolutions={false}
       cellMatcher={DEFAULT_CELL_MATCHER}
       data={validData}
       id="test"
@@ -89,6 +92,7 @@ test('it displays error with invalid guess grid', () => {
   render(
     <Crossword
       allowedHtmlTags={DEFAULT_HTML_TAGS}
+      allowMissingSolutions={false}
       cellMatcher={DEFAULT_CELL_MATCHER}
       data={validData}
       id="test"
@@ -109,6 +113,7 @@ test.skip('it calls saveGrid', () => {
   render(
     <Crossword
       allowedHtmlTags={DEFAULT_HTML_TAGS}
+      allowMissingSolutions={false}
       cellMatcher={DEFAULT_CELL_MATCHER}
       data={validData}
       id="test"
@@ -126,7 +131,7 @@ test.skip('it calls saveGrid', () => {
   fireEvent.keyDown(grid, { key: 'A', code: 'KeyA' });
 
   act(() => {
-    jest.advanceTimersByTime(debounceTime);
+    jest.advanceTimersByTime(DEBOUNCE_TIME);
   });
   expect(saveGrid).toHaveBeenCalledTimes(2);
 
@@ -142,6 +147,7 @@ test('it always shows sticky clue', async () => {
   render(
     <Crossword
       allowedHtmlTags={DEFAULT_HTML_TAGS}
+      allowMissingSolutions={false}
       cellMatcher={DEFAULT_CELL_MATCHER}
       data={validData}
       id="test"
@@ -162,6 +168,7 @@ test('it never shows sticky clue', async () => {
   render(
     <Crossword
       allowedHtmlTags={DEFAULT_HTML_TAGS}
+      allowMissingSolutions={false}
       cellMatcher={DEFAULT_CELL_MATCHER}
       data={validData}
       id="test"
@@ -183,6 +190,7 @@ test('it conditionally shows sticky clue', async () => {
   const { rerender } = render(
     <Crossword
       allowedHtmlTags={DEFAULT_HTML_TAGS}
+      allowMissingSolutions={false}
       cellMatcher={DEFAULT_CELL_MATCHER}
       data={validData}
       id="test"
@@ -202,6 +210,7 @@ test('it conditionally shows sticky clue', async () => {
   rerender(
     <Crossword
       allowedHtmlTags={DEFAULT_HTML_TAGS}
+      allowMissingSolutions={false}
       cellMatcher={DEFAULT_CELL_MATCHER}
       data={validData}
       id="test"
diff --git a/src/components/Crossword/Crossword.tsx b/src/components/Crossword/Crossword.tsx
index ad980f6..72f4f12 100644
--- a/src/components/Crossword/Crossword.tsx
+++ b/src/components/Crossword/Crossword.tsx
@@ -38,6 +38,7 @@ import { initialiseGuessGrid, validateGuessGrid } from './../../utils/guess';
 
 interface CrosswordProps {
   allowedHtmlTags: string[];
+  allowMissingSolutions: boolean;
   cellMatcher: RegExp;
   data: GuardianCrossword;
   id: string;
@@ -50,6 +51,7 @@ interface CrosswordProps {
 
 export default function Crossword({
   allowedHtmlTags,
+  allowMissingSolutions,
   cellMatcher,
   data,
   id,
@@ -98,12 +100,13 @@ export default function Crossword({
   React.useEffect(() => {
     try {
       // initialise cells
-      const initCells = initialiseCells(
-        data.dimensions.cols,
-        data.dimensions.rows,
-        data.entries,
-        loadGrid ?? guessGrid,
-      );
+      const initCells = initialiseCells({
+        cols: data.dimensions.cols,
+        rows: data.dimensions.rows,
+        entries: data.entries,
+        guessGrid: loadGrid ?? guessGrid,
+        allowMissingSolutions,
+      });
       dispatch(cellsActionUpdateGrid(initCells));
 
       // initialise clues
diff --git a/src/components/MyCrossword/MyCrossword.tsx b/src/components/MyCrossword/MyCrossword.tsx
index 161c510..081448f 100644
--- a/src/components/MyCrossword/MyCrossword.tsx
+++ b/src/components/MyCrossword/MyCrossword.tsx
@@ -28,6 +28,7 @@ type Theme =
 
 export interface MyCrosswordProps {
   allowedHtmlTags?: string[];
+  allowMissingSolutions?: boolean;
   cellMatcher?: RegExp;
   className?: string;
   data: GuardianCrossword;
@@ -42,6 +43,7 @@ export interface MyCrosswordProps {
 
 export default function MyCrossword({
   allowedHtmlTags = DEFAULT_HTML_TAGS,
+  allowMissingSolutions = false,
   cellMatcher = DEFAULT_CELL_MATCHER,
   className,
   data,
@@ -67,6 +69,7 @@ export default function MyCrossword({
       <Provider store={store}>
         <Crossword
           allowedHtmlTags={allowedHtmlTags}
+          allowMissingSolutions={allowMissingSolutions}
           cellMatcher={cellMatcher}
           data={data}
           id={id}
diff --git a/src/redux/cellsSlice.test.ts b/src/redux/cellsSlice.test.ts
index d89dc8a..df32be9 100644
--- a/src/redux/cellsSlice.test.ts
+++ b/src/redux/cellsSlice.test.ts
@@ -10,11 +10,11 @@ function getState() {
 }
 
 test('it updates grid', () => {
-  const cells = initialiseCells(
-    testData.dimensions.cols,
-    testData.dimensions.rows,
-    testData.entries,
-  );
+  const cells = initialiseCells({
+    cols: testData.dimensions.cols,
+    rows: testData.dimensions.rows,
+    entries: testData.entries,
+  });
   store.dispatch(updateGrid(cells));
   expect(getState()).toStrictEqual(cells);
 });
diff --git a/src/redux/cluesSlice.test.ts b/src/redux/cluesSlice.test.ts
index 4c77189..4d6e5ad 100644
--- a/src/redux/cluesSlice.test.ts
+++ b/src/redux/cluesSlice.test.ts
@@ -17,11 +17,11 @@ function getState() {
 }
 
 test('it updates grid', () => {
-  const cells = initialiseCells(
-    testData.dimensions.cols,
-    testData.dimensions.rows,
-    testData.entries,
-  );
+  const cells = initialiseCells({
+    cols: testData.dimensions.cols,
+    rows: testData.dimensions.rows,
+    entries: testData.entries,
+  });
 
   const clues = initialiseClues(testData.entries, cells);
 
diff --git a/src/testData/test.incomplete.1.ts b/src/testData/test.incomplete.1.ts
new file mode 100644
index 0000000..182ec3e
--- /dev/null
+++ b/src/testData/test.incomplete.1.ts
@@ -0,0 +1,88 @@
+import type { GuardianCrossword } from '../interfaces';
+
+const data: GuardianCrossword = {
+  id: 'test/valid/1',
+  number: 1,
+  name: 'Valid Test 1',
+  date: 1542326400000,
+  entries: [
+    {
+      id: '1-across',
+      number: 1,
+      humanNumber: '1',
+      clue: 'Toy on a string (2-2)',
+      direction: 'across',
+      length: 4,
+      group: ['1-across'],
+      position: { x: 0, y: 0 },
+      separatorLocations: {
+        '-': [2],
+      },
+      solution: 'YOY',
+    },
+    {
+      id: '4-across',
+      number: 4,
+      humanNumber: '4',
+      clue: 'Have a rest (3,4)',
+      direction: 'across',
+      length: 7,
+      group: ['4-across'],
+      position: { x: 0, y: 2 },
+      separatorLocations: {
+        ',': [3],
+      },
+      solution: 'LIEDOWN',
+    },
+    {
+      id: '1-down',
+      number: 1,
+      humanNumber: '1',
+      clue: 'Colour (6)',
+      direction: 'down',
+      length: 6,
+      group: ['1-down'],
+      position: { x: 0, y: 0 },
+      separatorLocations: {},
+      solution: '',
+    },
+    {
+      id: '2-down',
+      number: 2,
+      humanNumber: '2',
+      clue: 'Bits and bobs (4,3,4)',
+      direction: 'down',
+      length: 7,
+      group: ['2-down', '3-down'],
+      position: { x: 3, y: 0 },
+      separatorLocations: {
+        ',': [4, 7],
+      },
+      solution: 'ODDSAND',
+    },
+    {
+      id: '3-down',
+      number: 3,
+      humanNumber: '3',
+      clue: 'See 2',
+      direction: 'down',
+      length: 4,
+      group: ['2-down', '3-down'],
+      position: {
+        x: 6,
+        y: 1,
+      },
+      separatorLocations: {},
+      solution: 'ENDS',
+    },
+  ],
+  solutionAvailable: true,
+  dateSolutionAvailable: 1542326400000,
+  dimensions: {
+    cols: 13,
+    rows: 13,
+  },
+  crosswordType: 'quick',
+};
+
+export default data;
diff --git a/src/utils/cell.test.ts b/src/utils/cell.test.ts
index e3bfbe4..5d1b27d 100644
--- a/src/utils/cell.test.ts
+++ b/src/utils/cell.test.ts
@@ -1,5 +1,6 @@
 import { Char } from '../interfaces';
 import { revealGrid as cellsActionRevealGrid } from '../redux/cellsSlice';
+import incompleteData from '../testData/test.incomplete.1';
 import invalidData1 from '../testData/test.invalid.1';
 import invalidData2 from '../testData/test.invalid.2';
 import invalidData3 from '../testData/test.invalid.3';
@@ -95,80 +96,101 @@ test('blankNeighbours without neighbours', () => {
 
 test('initialiseCells with invalid data 1', () => {
   expect(() =>
-    initialiseCells(
-      invalidData1.dimensions.cols,
-      invalidData1.dimensions.rows,
-      invalidData1.entries,
-    ),
+    initialiseCells({
+      cols: invalidData1.dimensions.cols,
+      rows: invalidData1.dimensions.rows,
+      entries: invalidData1.entries,
+    }),
   ).toThrow('Crossword data error: solution length mismatch');
 });
 
 test('initialiseCells with invalid data 2', () => {
   expect(() =>
-    initialiseCells(
-      invalidData2.dimensions.cols,
-      invalidData2.dimensions.rows,
-      invalidData2.entries,
-    ),
+    initialiseCells({
+      cols: invalidData2.dimensions.cols,
+      rows: invalidData2.dimensions.rows,
+      entries: invalidData2.entries,
+    }),
   ).toThrow('Crossword data error: out of bounds');
 });
 
 test('initialiseCells with invalid data 3', () => {
   expect(() =>
-    initialiseCells(
-      invalidData3.dimensions.cols,
-      invalidData3.dimensions.rows,
-      invalidData3.entries,
-    ),
+    initialiseCells({
+      cols: invalidData3.dimensions.cols,
+      rows: invalidData3.dimensions.rows,
+      entries: invalidData3.entries,
+    }),
   ).toThrow('Crossword data error: solution character clash');
 });
 
 test('initialiseCells with invalid data 4', () => {
   expect(() =>
-    initialiseCells(
-      invalidData4.dimensions.cols,
-      invalidData4.dimensions.rows,
-      invalidData4.entries,
-    ),
+    initialiseCells({
+      cols: invalidData4.dimensions.cols,
+      rows: invalidData4.dimensions.rows,
+      entries: invalidData4.entries,
+    }),
   ).toThrow('Crossword data error: overlapping across solutions');
 });
 
 test('initialiseCells with invalid data 5', () => {
   expect(() =>
-    initialiseCells(
-      invalidData5.dimensions.cols,
-      invalidData5.dimensions.rows,
-      invalidData5.entries,
-    ),
+    initialiseCells({
+      cols: invalidData5.dimensions.cols,
+      rows: invalidData5.dimensions.rows,
+      entries: invalidData5.entries,
+    }),
   ).toThrow('Crossword data error: overlapping down solutions');
 });
 
 test('initialiseCells with invalid data 6', () => {
   expect(() =>
-    initialiseCells(
-      invalidData6.dimensions.cols,
-      invalidData6.dimensions.rows,
-      invalidData6.entries,
-    ),
+    initialiseCells({
+      cols: invalidData6.dimensions.cols,
+      rows: invalidData6.dimensions.rows,
+      entries: invalidData6.entries,
+    }),
   ).toThrow('Crossword data error: clue id missing from group');
 });
 
 test('initialiseCells with invalid data 7', () => {
   expect(() =>
-    initialiseCells(
-      invalidData7.dimensions.cols,
-      invalidData7.dimensions.rows,
-      invalidData7.entries,
-    ),
+    initialiseCells({
+      cols: invalidData7.dimensions.cols,
+      rows: invalidData7.dimensions.rows,
+      entries: invalidData7.entries,
+    }),
   ).toThrow('Crossword data error: group clue id not found');
 });
 
+test('initialiseCells with incomplete data', () => {
+  expect(() =>
+    initialiseCells({
+      cols: incompleteData.dimensions.cols,
+      rows: incompleteData.dimensions.rows,
+      entries: incompleteData.entries,
+    }),
+  ).toThrow('Crossword data error: solution length mismatch');
+});
+
+test('initialiseCells with incomplete data (allowed)', () => {
+  expect(() =>
+    initialiseCells({
+      cols: incompleteData.dimensions.cols,
+      rows: incompleteData.dimensions.rows,
+      entries: incompleteData.entries,
+      allowMissingSolutions: true,
+    }),
+  ).not.toThrow('Crossword data error: solution length mismatch');
+});
+
 test('initialiseCells with valid data', () => {
-  const cells = initialiseCells(
-    validData.dimensions.cols,
-    validData.dimensions.rows,
-    validData.entries,
-  );
+  const cells = initialiseCells({
+    cols: validData.dimensions.cols,
+    rows: validData.dimensions.rows,
+    entries: validData.entries,
+  });
 
   expect(cells.length).toBe(23);
   expect(cells).toEqual([
@@ -366,12 +388,12 @@ test('initialiseCells with valid data and guess grid', () => {
     validData.dimensions.rows,
     gridChar,
   );
-  const cells = initialiseCells(
-    validData.dimensions.cols,
-    validData.dimensions.rows,
-    validData.entries,
+  const cells = initialiseCells({
+    cols: validData.dimensions.cols,
+    rows: validData.dimensions.rows,
+    entries: validData.entries,
     guessGrid,
-  );
+  });
 
   expect(cells.length).toBe(23);
   expect(cells).toEqual([
diff --git a/src/utils/cell.ts b/src/utils/cell.ts
index f9b4043..7a951d2 100644
--- a/src/utils/cell.ts
+++ b/src/utils/cell.ts
@@ -46,12 +46,19 @@ export function blankNeighbours(
  * @param entries
  * @returns
  */
-export function initialiseCells(
-  cols: number,
-  rows: number,
-  entries: GuardianClue[],
-  guessGrid?: GuessGrid,
-) {
+export function initialiseCells({
+  cols,
+  rows,
+  entries,
+  guessGrid,
+  allowMissingSolutions = false,
+}: {
+  cols: number;
+  rows: number;
+  entries: GuardianClue[];
+  guessGrid?: GuessGrid;
+  allowMissingSolutions?: boolean;
+}) {
   const cells: Cell[] = [];
   const entryIds = entries.map((entry) => entry.id);
 
@@ -64,14 +71,21 @@ export function initialiseCells(
       // grid validation
       if (col < 0 || col >= cols || row < 0 || row >= rows) {
         throw new Error('Crossword data error: out of bounds');
-      } else if (
+      }
+
+      if (
+        !allowMissingSolutions &&
         entry.solution !== undefined &&
         entry.length !== entry.solution.length
       ) {
         throw new Error('Crossword data error: solution length mismatch');
-      } else if (!entry.group.includes(entry.id)) {
+      }
+
+      if (!entry.group.includes(entry.id)) {
         throw new Error('Crossword data error: clue id missing from group');
-      } else if (!entry.group.every((clueId) => entryIds.includes(clueId))) {
+      }
+
+      if (!entry.group.every((clueId) => entryIds.includes(clueId))) {
         throw new Error('Crossword data error: group clue id not found');
       }
 
@@ -95,22 +109,33 @@ export function initialiseCells(
 
         cells.push(newCell);
       } else {
-        // merge cell
-        if (currentCell.val !== entry.solution?.[i]) {
-          throw new Error('Crossword data error: solution character clash');
-        } else if (
+        if (
           across &&
           currentCell.clueIds.some((clueId) => clueId.endsWith('across'))
         ) {
           throw new Error('Crossword data error: overlapping across solutions');
-        } else if (
+        }
+
+        if (
           !across &&
           currentCell.clueIds.some((clueId) => clueId.endsWith('down'))
         ) {
           throw new Error('Crossword data error: overlapping down solutions');
-        } else {
-          currentCell.num = i === 0 ? entry.number : currentCell.num;
-          currentCell.clueIds = [...currentCell.clueIds, entry.id];
+        }
+
+        const newChar = entry.solution?.[i];
+
+        if (!allowMissingSolutions && currentCell.val !== newChar) {
+          throw new Error('Crossword data error: solution character clash');
+        }
+
+        // merge cell
+        currentCell.num = i === 0 ? entry.number : currentCell.num;
+        currentCell.clueIds = [...currentCell.clueIds, entry.id];
+
+        // overwrite with new value
+        if (allowMissingSolutions && newChar !== undefined) {
+          currentCell.val = newChar as Char;
         }
       }
     }
diff --git a/src/utils/clue.test.ts b/src/utils/clue.test.ts
index 1f3acb9..ec09f35 100644
--- a/src/utils/clue.test.ts
+++ b/src/utils/clue.test.ts
@@ -152,11 +152,11 @@ describe('getCrossingClueIds', () => {
 
 describe('initialiseClues', () => {
   test('clues get initialised', () => {
-    const cells = initialiseCells(
-      testData.dimensions.cols,
-      testData.dimensions.rows,
-      testData.entries,
-    );
+    const cells = initialiseCells({
+      cols: testData.dimensions.cols,
+      rows: testData.dimensions.rows,
+      entries: testData.entries,
+    });
 
     const clues = initialiseClues(testData.entries, cells);
     expect(clues).toEqual([
@@ -234,11 +234,11 @@ describe('initialiseClues', () => {
   });
 
   test('clues get initialised with selected clue', () => {
-    const cells = initialiseCells(
-      testData.dimensions.cols,
-      testData.dimensions.rows,
-      testData.entries,
-    );
+    const cells = initialiseCells({
+      cols: testData.dimensions.cols,
+      rows: testData.dimensions.rows,
+      entries: testData.entries,
+    });
 
     const clues = initialiseClues(testData.entries, cells, '1-across');
     expect(clues).toEqual(
@@ -262,11 +262,11 @@ describe('initialiseClues', () => {
   });
 
   test('clues get initialised with answered clues', () => {
-    const cells = initialiseCells(
-      testData.dimensions.cols,
-      testData.dimensions.rows,
-      testData.entries,
-    );
+    const cells = initialiseCells({
+      cols: testData.dimensions.cols,
+      rows: testData.dimensions.rows,
+      entries: testData.entries,
+    });
 
     // reveal all cells
     store.dispatch(cellsUpdateGrid(cells));
diff --git a/src/utils/test.ts b/src/utils/test.ts
index ec3e20d..483f716 100644
--- a/src/utils/test.ts
+++ b/src/utils/test.ts
@@ -11,12 +11,12 @@ export function initialiseStore(
   data: GuardianCrossword,
   guessGrid?: GuessGrid,
 ) {
-  const cells = initialiseCells(
-    data.dimensions.cols,
-    data.dimensions.rows,
-    data.entries,
+  const cells = initialiseCells({
+    cols: data.dimensions.cols,
+    rows: data.dimensions.rows,
+    entries: data.entries,
     guessGrid,
-  );
+  });
 
   const clues = initialiseClues(data.entries, cells);