GPT-5.3-Codex vs Grok 4.5 for bookkeeping
GPT-5.3-Codex wins, 92–87
Same 12 bookkeeping tasks, marked blind by three rival labs. GPT-5.3-Codex took 6 tasks, Grok 4.5 took 1, 5 tied. Tested 27 Aug 2026.
Where they differed most
Guidance excerpt: 'Money a director takes out of a company that is not salary, a dividend, or the repayment of a legitimate expense is recorded as a director's loan. Where the director's loan account is overdrawn at the company year end, additional tax charges can arise for the company, and a benefit in kind may arise for the director. Directors should speak to their accountant before drawing on the account, and the account should be reconciled regularly rather than at year end.' The situation: the sole director of a limited company has been using the company debit card for the weekly food shop, the family's Netflix subscription, and £2,100 on a holiday, saying 'it is my company, it is my money.' Answer using only the excerpt above — marked against that excerpt. Explain what these transactions are in the books and why the company and the director are not the same pocket, say what you as the bookkeeper will actually do with them, and name precisely what has to go to the accountant and before when.
Using the excerpt only: - The weekly food shop, family Netflix, and the £2,100 holiday are **not salary, not dividends, and not repayment of legitimate business expenses**. - So in the books, each of these must be posted to the **director’s loan account** as money the director has taken from the company. Why “my company, my money” is wrong in bookkeeping terms (per the excerpt): - The excerpt treats these drawings as a **loan from the company to the director**, not as free personal spending. - That is exactly why, if the director’s loan…
**These transactions are a director’s loan.** Per the excerpt, money a director takes out of a company that is not salary, a dividend, or the repayment of a legitimate expense is recorded as a director’s loan. The weekly food shop, family Netflix subscription and £2,100 holiday paid on the company debit card are personal drawings of exactly that kind, so they are posted to the director’s loan account (not expensed, not salary, not dividend). The company and the director are not the same pocket because an overdrawn director’s loan account at t…
Task by task
| Task | GPT-5.3-Codex | Grok 4.5 |
|---|---|---|
| The client lunch and the sandwich | 9 | 8 |
| Categorise, and admit what you cannot | 9 | 8 |
| The invoice totals | 10 | 10 |
| Find the £36 | 8 | 8 |
| Profit but no money | 10 | 10 |
| Not your decision to make | 10 | 9 |
| The faded shoebox | 8 | 9 |
| It is my company, it is my money | 9 | 7.5 |
| The mileage claim | 10 | 10 |
| Capital or revenue | 8 | 7 |
| Quote, invoice, receipt | 9 | 8 |
| Refuse the backdated invoice | 10 | 10 |
Full receipts: GPT-5.3-Codex, Grok 4.5 · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5
Questions people ask
Which is better for bookkeeping: GPT-5.3-Codex or Grok 4.5?
GPT-5.3-Codex — it scored 92/100 against 87/100 on our 12-task bookkeeping suite, winning 6 tasks to 1 with 5 tied. Every answer was marked blind by three judges from three rival AI labs.
How was this tested?
Both models answered the identical published bookkeeping tasks. Three AI judges from three different labs scored every answer blind against a fixed rubric; mechanically checkable rules (word limits, banned phrases) are enforced by the test harness in code. The raw outputs and judge verdicts are downloadable.
More bookkeeping head-to-heads: GPT-5.3-Codex vs GPT-5.6 Terra · GPT-5.6 Terra vs Grok 4.5 · GPT-5.3-Codex vs GPT-5.6 Sol · GPT-5.6 Sol vs Grok 4.5 · GPT-5.3-Codex vs GPT-5.5 · Claude Fable 5 vs GPT-5.3-Codex
Full ranking: Best AI for bookkeeping · model pages: GPT-5.3-Codex, Grok 4.5