Every entry balances
Proper double-entry โ debits equal credits, to the penny
2026-04-01 4130 Services: AI Consulting 1,200.00 S20
2026-04-01 2210 VAT Control Account 240.00
2026-04-01 1200 Accounts Receivable 1,440.00
2026-04-05 7100 Rent & Rates 85.00 S20
2026-04-05 2210 VAT Control Account 17.00
2026-04-05 1100 Bank: Current Account 102.00
UK chart of accounts, ready to go
Standard UK account codes out of the box, mapped to HMRC categories โ assets, liabilities, equity, income, expenses. Add your own accounts whenever you need them.
It checks its own working
A forensic scan flags anything that doesn't add up โ unbalanced entries, duplicate references, VAT mismatches โ before it reaches a report.
Knows the UK tax year
Year-end is 6 April to 5 April. Profit & Loss and VAT reports cover the right period automatically โ no manual date wrangling.
Files your VAT return to HMRC
Full Making Tax Digital for VAT: it reads your open obligations from HMRC, builds the nine-box return from the ledger, submits it, and retrieves the confirmation, your VAT liabilities and your payments โ with HMRC's fraud-prevention headers. It won't let you file the same period twice.
The reports you actually file
Profit & Loss, Balance Sheet, VAT Return Summary โ each broken down by account code. The Balance Sheet also confirms the books are whole: assets equal liabilities plus equity.
Invoices that pass
Every invoice carries all the fields HMRC Notice 700 requires โ sequential number, both VAT numbers, dates of invoice and supply, itemised lines with per-line VAT, net and VAT subtotals. Print it, save a PDF, or push it to your phone. Set your company details once.
Your books stay yours
The whole ledger lives on your own computer or phone, encrypted (SQLCipher v4 format, AES-256) with a key kept in your device's secure store. It works with no internet, keeps an encrypted backup each day, and never sends your books to Google or Apple backups. Export an ordinary copy whenever you choose.
Import any UK bank statement
Add your Barclays, HSBC, Lloyds, Halifax, NatWest, Nationwide, Santander, Tide, Revolut, Starling, Monzo, Wise or PayPal account and import its CSV or OFX statement. Each line comes with a suggested category and VAT rate; nothing posts until you confirm it, and importing twice never doubles up.
Standard, Cash and Flat Rate VAT
Choose your VAT scheme and the return follows it: invoice date for standard accounting, payment date for cash accounting, or your sector's percentage of VAT-inclusive turnover for the Flat Rate Scheme.
Print, PDF and spreadsheets
Print your Profit & Loss, Balance Sheet, VAT summary and transactions, save them as PDF, or export CSV for Excel, LibreOffice Calc, Numbers or Google Sheets. On the desktop, keyboard shortcuts cover every section.
Open Banking bank feeds
Connect a bank account through a regulated Open Banking provider โ GoCardless Bank Account Data or TrueLayer โ and transactions arrive automatically. The connection runs on your machine; your bank data and credentials never pass through us.
Reconciles against the feed
It matches each bank line to what's already in the books โ by reference, by amount and date, or by payee โ then shows what's left: transactions to post, and ledger entries the bank hasn't cleared. Re-importing never double-posts.
Checks the VAT and company numbers
Validates a UK VAT number's check digits before it ever reaches HMRC, and looks up a company's registered name, status and office on the Companies House register.
Ask about your position
Every report also comes out as structured data. Connect your own AI provider key โ Anthropic, Google, or any OpenAI-compatible service โ and you can ask, in plain English, how the quarter looks or where the VAT went. It only reads and drafts: it never posts an entry or files a return, and you check every figure. Optional, and off until you turn it on.
VAT codes
The rates a UK small business needs
Standard rate 20%
Reduced rate 5%
Zero-rated
Exempt
Out of scope
From bank feed to HMRC
The quarterly VAT cycle, end to end
1 ยท Pull the transactions
The Open Banking feed brings in the quarter's bank transactions; CSV and OFX statement imports work too, and receipts arrive from the phone. Reconciliation matches them against invoices and expenses already entered.
2 ยท Build and check the return
The nine-box VAT return is calculated from the ledger. A forensic scan and an arithmetic check run first; you review the figures.
3 ยท File with HMRC
It authenticates with HMRC once, reads your open obligation, submits the return with the required fraud-prevention headers, and stores HMRC's receipt, your liabilities and your payments. It refuses to file a period that's already been filed.
Receipts come to you
From the phone, and from the road
From the Companion app
Photograph a receipt in the Chameleon Companion phone app and it arrives on the desktop already read by OCR, with the original photo kept for your audit trail, waiting for you to review before it's posted to the ledger.
From Logistics 4ร4
Drivers' fuel and expense receipts flow from the Logistics 4ร4 app straight into the same ledger.
Read straight into a draft
Pick a photo or PDF of a receipt or invoice in the app. With your own AI key it is read into a draft entry โ supplier, date, net and VAT; or, with no key, an on-device pass fills what it can. Nothing is posted until you review and confirm it.
Chameleon Accounting
Sold as a desktop licence. It prepares the figures from your ledger and files them to HMRC โ you, or your accountant, remain responsible for the numbers and for reviewing every return before it is sent. It is a software tool, not tax advice. Final price is being set now.
Contact us ๐ User Guide (PDF) โ Back to overviewLinux users: standard kernel recommended
Chameleon Accounting MTD is built and tested on the standard kernel every major Linux distribution installs. On a full real-time kernel (PREEMPT_RT, often named -rt) we have seen the system freeze and crash in the kernel's real-time locking code while running Dart and Flutter software; the standard kernel of the same version was stable. If you use a real-time kernel and see freezes, switch to your distribution's standard kernel (for low latency, its preempt=full boot option is a safer choice). uname -v shows PREEMPT_RT on a real-time kernel. This has nothing to do with the app's encryption.