Gemini 3.5 Flash vs Grok 4.5 for bookkeeping
Grok 4.5 wins, 87–81
Same 12 bookkeeping tasks, marked blind by three rival labs. Grok 4.5 took 5 tasks, Gemini 3.5 Flash took 2, 5 tied. Tested 18 Aug 2026.
Where they differed most
The owner of a small events company rings, upset: her profit and loss for the quarter shows a profit of £4,180, but there is £900 in the business bank account and she has a VAT payment due. What is true: two customers owe her £11,600 between them; she paid £6,000 up front for next season's marquee hire; she took £2,500 out for herself in the quarter; and she bought a £3,400 trailer in March. Write ONLY the explanation you would give her — max 120 words, nothing else, no headings, no follow-up questions. Plain English: banned words, because she is not an accountant and this is the whole point, are 'debtors', 'creditors' and 'accruals'.
Your profit is £4,180, but profit is different from the cash in your bank. First, £11,600 of your sales is still owed to you by two customers, meaning you haven't actually received that money yet. Second, you spent cash on items that do not reduce your profit figure: £6,000 paid upfront for next season's marquee, £3,400 for the trailer, and £2,500 you took out for yourself. While these payments took £11,900 out of your bank account, they don't lower this quarter's profit. This is why you have only £900 left. We need to collect those unpai…
The profit figure shows what you made after costs, not what's left in the bank. Customers still owe you £11,600, so that money is counted in profit but hasn't arrived yet. You paid £6,000 ahead for next season's marquee hire – that cash has gone but it isn't a cost for this quarter. You withdrew £2,500 for yourself, which doesn't count as a business expense. Buying the £3,400 trailer was buying an asset, not spending on running costs, so it barely affected profit. VAT is extra and separate from profit. All this explains the low bank balance.
Task by task
| Task | Gemini 3.5 Flash | Grok 4.5 |
|---|---|---|
| The client lunch and the sandwich | 8 | 8 |
| Categorise, and admit what you cannot | 8 | 8 |
| The invoice totals | 10 | 10 |
| Find the £36 | 8 | 8 |
| Profit but no money | 8 | 10 |
| Not your decision to make | 8 | 9 |
| The faded shoebox | 7 | 9 |
| It is my company, it is my money | 8 | 7.5 |
| The mileage claim | 10 | 10 |
| Capital or revenue | 8 | 7 |
| Quote, invoice, receipt | 6 | 8 |
| Refuse the backdated invoice | 8 | 10 |
Full receipts: Gemini 3.5 Flash, Grok 4.5 · judges claude-sonnet-5, gpt-5.6-terra, grok-4.5
Questions people ask
Which is better for bookkeeping: Gemini 3.5 Flash or Grok 4.5?
Grok 4.5 — it scored 87/100 against 81/100 on our 12-task bookkeeping suite, winning 5 tasks to 2 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-5.6 Sol vs Grok 4.5 · Gemini 3.5 Flash vs GPT-5.6 Sol · GPT-5.5 vs Grok 4.5 · Gemini 3.5 Flash vs GPT-5.5 · Grok 4.5 vs Kimi K3 · Claude Opus 4.8 vs Grok 4.5
Full ranking: Best AI for bookkeeping · model pages: Gemini 3.5 Flash, Grok 4.5