Self Assessment
Live — Available nowYour SA100 and SA103 self-employment pages, drafted from your reconciled books, filed direct to HMRC.
See the product →Live — Available nowIncluded in Sole trader · from £14/mo
Accounting software for sole traders
ac-co keeps a sole trader's books reconciled from your bank feed, works out what you owe as you go, and drafts your Self Assessment from those same numbers — so 31 January is a review, not a scramble.
In this stack
OBLIGATIONS CALENDAR
A year in your stack, with what we do on each date.
6 April – 5 April
- Your tax year, reconciled as it happensEvery transaction categorised and matched to a receipt, not batched in January.
31 January
- SA100 + SA103 filedSubmitted to HMRC with a receipt.
- Balancing payment and first payment on account due
31 July
- Second payment on account dueCalculated from your filed return, not a guess.
Once MTD ITSA applies to you
- Quarterly update filedDrafted from the same reconciled books — no separate re-entry.
Sole trader
£14
or £140/yr, paid annually
- ✓MTD ITSA quarterly updates, £0 on this plan
- ✓VAT return drafted from the same books if you register
- ✓Books included — one ledger, not three exports
HOW IT FITS TOGETHER
From connected to filed.
01
Connect your bank
Read-only Open Banking access — no statements to upload, no spreadsheet to keep.
02
Books stay reconciled
Every transaction is categorised and matched to a receipt automatically, so your profit figure is always current.
03
Your return drafts itself
Self Assessment reads straight off those books, fills the SA103 self-employment pages, and waits for your sign-off before it files.
No sign-up — try it right here
See your Income Tax and Class 4 NI estimate.
The same maths your Self Assessment draft uses — enter this year's profit and see roughly what's due.
An estimate from the figures you enter, not a filed calculation. Your actual bill depends on your full return. Open the full calculator →
COMPARE
A sole trader's three ways to get it filed.
| Row | HMRC online + a spreadsheet | A high-street accountant | ac-co |
|---|---|---|---|
| £/year | Free | £150–£300/yr [Crunch — packages pricing, 2026-09-13] | From £14/mo, or £65 to file |
| Hours/year | ~6 hours | ~1 hour, plus waiting | ~10 minutes |
| Reads your bank feed automatically | No | If you send them statements | Yes |
| Recognised by HMRC for SA100 | It is HMRC | Their software, not them | Yes |
Accountant fee is a published rate-card range, read 2026-09-13 — check your own quote.
YOUR STACK
Every part of ac-co built for this.
Each one carries its real status — no product here is described as more finished than it is.
Books
Beta — Open beta — join the waitlist, we open seats in batchesBank feed in, transactions categorised and reconciled automatically — the ledger your tax return is built from.
See the product →VAT
Beta — Open beta — join the waitlist, we open seats in batchesIf you're VAT-registered, quarterly returns drafted from the same books and filed under MTD.
See the product →Income Tax (MTD)
Beta — Open beta — join the waitlist, we open seats in batchesWhen Making Tax Digital for Income Tax reaches your turnover band, your quarterly updates draft themselves — no separate re-entry.
See the product →Where to go next
OBJECTIONS
Before you sign up.
What if I get something wrong?
Every figure traces to the bank transaction or receipt behind it, and you review the SA100 before it's sent — nothing files itself unchecked.
Do I need to register for Self Assessment at all?
Only once your self-employed income passes £1,000 in the tax year — below that you don't need to file. (Source: gov.uk, https://www.gov.uk/simpler-income-tax-simplifications/trading-and-property-allowances.)
I already have an accountant — can they still help?
Yes — invite them into the same workspace to review before anything is filed; nothing here requires dropping them.
What if I'm also VAT-registered?
Your VAT return drafts from the same reconciled books, so you're not re-entering the same transactions twice.
What happens to my data if I leave?
You export your ledger and documents whenever you like — nothing is held hostage.
Start today.
Connect your bank once — everything above reads from the same reconciled numbers.