Gemini 3.5 Flash vs GPT-5.6 Sol for bookkeeping
GPT-5.6 Sol wins, 93–81
Same 12 bookkeeping tasks, marked blind by three rival labs. GPT-5.6 Sol took 7 tasks, Gemini 3.5 Flash took 0, 5 tied. Tested 18 Aug 2026.
Where they differed most
Guidance excerpt: 'You must keep records of all sales and expenses. Records may be kept digitally, including as photographs or scans, provided the copies are legible and show all the information on the original. Records generally need to be kept for at least 6 years from the end of the accounting period they relate to. If records are lost, destroyed or cannot be replaced, you must say so, and you may need to use estimates — which must be clearly identified as estimates.' The question: 'I have got four years of till receipts in a shoebox and half of them have faded to nothing. I have photographed the ones you can still read. Can I bin the paper? And what do I do about the blank ones?' Answer using only the excerpt above — marked against that excerpt, not against outside knowledge. Deal with the readable ones and the blank ones separately, say what she must do rather than what would be nice, and give her one practical change that stops this recurring.
Based on the provided excerpt, here is what you must do: **For the readable receipts:** * **Can you bin the paper?** Yes, you can dispose of the paper receipts and keep them digitally as photographs, **provided** the digital copies are legible and show all the information that was on the original. * **What you must do:** You must keep these digital records for at least 6 years from the end of the accounting period they relate to (meaning you must retain them for at least another 2 years, as you currently only have 4 years of receipts). **For…
**Readable receipts:** You may bin the paper if each photograph is legible, shows all the information on the original, and is kept digitally for at least six years from the end of the relevant accounting period. **Blank/faded receipts:** Treat these as lost or irrecoverable records. You must state that they cannot be replaced. If you need to reconstruct the sales or expenses using estimates, clearly identify them as estimates. **To prevent this recurring:** Photograph or scan every receipt while it is still readable, checking that the image i…
Task by task
| Task | Gemini 3.5 Flash | GPT-5.6 Sol |
|---|---|---|
| The client lunch and the sandwich | 8 | 8 |
| Categorise, and admit what you cannot | 8 | 9 |
| The invoice totals | 10 | 10 |
| Find the £36 | 8 | 9 |
| Profit but no money | 8 | 8 |
| Not your decision to make | 8 | 10 |
| The faded shoebox | 7 | 10 |
| It is my company, it is my money | 8 | 8 |
| The mileage claim | 10 | 10 |
| Capital or revenue | 8 | 10 |
| Quote, invoice, receipt | 6 | 9 |
| Refuse the backdated invoice | 8 | 10 |
Full receipts: Gemini 3.5 Flash, GPT-5.6 Sol · judges claude-sonnet-5, gpt-5.6-terra, grok-4.5
Questions people ask
Which is better for bookkeeping: Gemini 3.5 Flash or GPT-5.6 Sol?
GPT-5.6 Sol — it scored 93/100 against 81/100 on our 12-task bookkeeping suite, winning 7 tasks to 0 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-5.5 vs GPT-5.6 Sol · GPT-5.6 Sol vs Grok 4.5 · GPT-5.6 Sol vs Kimi K3 · Claude Opus 4.8 vs GPT-5.6 Sol · GLM 5.2 vs GPT-5.6 Sol · Claude Sonnet 5 vs GPT-5.6 Sol
Full ranking: Best AI for bookkeeping · model pages: Gemini 3.5 Flash, GPT-5.6 Sol