ac-co vs TaxCalc — which Self Assessment route fits you?
TaxCalc is long-established desktop tax-return software: you buy an annual licence, install it, and work through a guided “SimpleStep” wizard yourself. ac-co is cloud software that drafts the return from your connected accounts, so there's no wizard to work through box by box.
ac-co vs TaxCalc, row by row.
Where we're weaker, we say so. Every ac-co fact comes from our own product pages; every competitor fact comes from their public site, cited below.
| What you get | ac-coSA100 | TaxCalcfrom £42 |
|---|---|---|
| Price | £29–£65 per return (50% off until 14 January 2027; full price £59–£129) | From £42 (annual licence, desktop software) |
| Free to start | Start free, no card — you pay only when you file | Not stated |
| Files direct to HMRC | Yes | Yes |
| Who reviews before filing | You review and approve — not an accountant | You — desktop DIY software with a built-in “Check & Finish” error scan, no accountant review |
| Supplementary pages | 11 supported — SA102, 103, 104, 105, 106, 108 (shares & crypto), 109 + more | “All supplementary pages, including non-residence and complex income” |
| MTD Income Tax quarterly updates | Beta — quarterly updates drafted from your ledger, on the waitlist | Listed as a separate product for individuals; price not shown on the site |
| File it from ChatGPT or Claude | Yes — file from ChatGPT, Claude or Codex (MCP) | Not offered |
| Bookkeeping included | Available — ac-co.books (beta), from £9/month | No |
| Mobile app | No — web app only (works fine in a mobile browser) | Not stated |
| Best for | You'd rather your return was drafted from your bank, accounts and broker than built by hand in a desktop wizard. | You're comfortable with desktop software and want to own a one-off annual licence rather than pay per return. |
Competitor details for TaxCalc are from taxcalc.com/individual (opens in a new tab), checked on 2026-09-10 — check their site for anything that may have changed since. TaxCalc is a trademark of its owner; ac-co.ai is not affiliated.
Neither is wrong — it depends what you need.
Pick ac-co if you'd rather skip a step-by-step wizard entirely — connect your bank, accounts or broker and review a return that's already drafted, from any browser, on any device.
Pick TaxCalc if you're used to desktop tax software, want a one-off annual licence you install locally, and are happy entering your own figures through its guided SimpleStep mode.
No sign-up — see what you'd owe.
The same income tax engine that drafts your SA100 runs here. Nothing is saved unless you start a return.
An estimate from the figures you enter — not a tax calculation or advice. Your final figure comes from your filed Self Assessment return.
What moves across, and what it costs.
From Other
- ✓Prior-year figures, if you export them
- ✓Your UTR and HMRC login details
Switching from TaxCalc
ac-co vs TaxCalc — why would I move?
I've already bought this year's TaxCalc licence.
A genuine sunk cost if you're mid-year — it may make sense to finish this return on TaxCalc and try ac-co for your next one, priced per return instead of an annual licence.
I'm used to the desktop SimpleStep wizard.
ac-co runs entirely in the browser and drafts the return from your connected accounts rather than walking you through a step-by-step wizard — different workflow, not a worse one, but a genuine change if you like SimpleStep.
Does TaxCalc's install-on-two-computers licence save me money?
If you already own the licence and only need one return a year, it can. ac-co's per-return pricing (from £29) suits filing occasionally or wanting the price to reflect your return's actual complexity.
Will 'Check & Finish' catch things ac-co won't?
TaxCalc's error scan checks a return you've built by hand. ac-co's draft starts from your bank, accounts and HMRC's own pre-population, so many of the same errors — a missed box, a mismatched figure — are less likely to occur in the first place.
Is desktop software safer than a web app for something this sensitive?
Both file directly to HMRC. ac-co runs in the browser on any device without an install; TaxCalc is a local install you own outright — a reasonable preference either way, not a security gap on our side.