Your accounts and corporation tax, filed properly for £59.
Micro-entity accounts to Companies House and the CT600 to HMRC — computed, previewed free, and tracked to acceptance in one flow. One payment, never a subscription. Accepted or refunded.
Flat prices, no subscription
Every filing a small company owes.
£59
Trading year
FRS 105 accounts + CT600 with computations, both registers.
£29
Dormant year
Dormant accounts + nil CT600, both registers.
£39
Charity CT600E
Full exemption claimed, filed and tracked to HMRC.
£69
Confirmation statement
CS01 with the £50 government fee included.
£9
MTD VAT return
Per return, the arithmetic done for you — free while in beta.
One payment per filing, never a subscription. Rejected? Refiling is free — and if it can't be made acceptable, the fee comes back. That's in the terms, not the small print.
From search to submitted
Three steps, about fifteen minutes.
Look up your company
Company details, accounting periods and due dates arrive prefilled from the register.
Review the real documents
Enter the year's figures — or import a trial balance — and preview the exact documents, free.
File and track to acceptance
Pay one flat fee, submit to both registers, and watch each acknowledgement arrive live.
Proof, not promises
This is a real acceptance. The IDs are HMRC's own.
WrenTax generates the exact machine-readable documents the registers require, validates them against the official taxonomies, and shows you each register's own answer — because "sent" is not "accepted", and a half-filed year is how directors collect £100 penalties believing they were done.
This receipt is from our recognition testing against HMRC's and Companies House's own submission systems — the identifiers are theirs, verbatim. When you file, you get the same artefacts, kept forever.
Trading year — accounts + CT600
AcceptedSubmission recorded
Documents locked and queued for transmission.
Accounts delivered
Companies House's gateway acknowledged the accounts.
Submission no. TIBZ4J
CT600 accepted
HMRC's engine accepted the return with an IRmark receipt.
Correlation D4190A1904DC4707850E92518A297140
The honest comparison
Three ways to file a trading year. Only one is a flat £59.
| What matters | An accountant | Subscription software | WrenTax |
|---|---|---|---|
| A trading year, both registers | £300–£900 + VAT a year | £59–£99 + VAT, every year, even if you file once | £59, one payment, done |
| Seeing the documents before paying | You see a PDF, then sign | Preview after signup | Full iXBRL + CT600 preview, free, no account |
| Knowing it was actually accepted | “It's been sent off” | A status badge | Each register's own acknowledgement + IRmark receipt, live |
| If a register rejects it | Their problem, on their timescale | Varies | Reason in plain English, fix prefilled, refile free — or refunded |
Accountant figures are typical UK small-practice fees for micro-entity accounts plus a CT600; subscription figures are typical software-per-year pricing with VAT added at checkout. If your company needs judgement — R&D, groups, losses, property — an accountant is worth every penny, and we'll tell you so before you pay.
Built in the open
WrenTax is built by a founder who files these returns for his own company — including the messy long-first-year split. It's operated by UniBookTrade Ltd (company no. 17019570) — look us up with our own tool.
Engineered like it matters
- — Tax engine differential-tested against HMRC's calculator
- — Hundreds of automated tests before any change ships
- — One engine, from the free calculators to the filed return
Your data, plainly
- — Your Companies House auth code is never stored
- — HMRC connects via HMRC's own login, not your password
- — Cards are handled by Stripe; we never hold card details
Free, and genuinely useful
The most thorough free UK company tax tools we could build.
Corporation tax calculator
Marginal relief, associated companies, short periods and straddling years — computed correctly.
OpenFirst-year CT split
A first year over 12 months becomes two CT600s. See both, with both deadlines and payment references.
OpenDividend tax calculator
Salary and dividends stacked correctly for 2026/27, with your real take-home pay.
OpenQuestions, answered plainly
Common questions
Are these real filings, or an approximation?
The real thing. WrenTax generates the exact iXBRL accounts, tax computations and CT600 the registers require — not a summary or an approximation — validated against the official Companies House and HMRC taxonomies before you ever see them, and stamped with a genuine IRmark computed to HMRC's published specification.
How much does it cost?
One payment per year of filings, no subscription. £59 files a trading year in full: FRS 105 micro-entity accounts to Companies House, plus the CT600 with iXBRL computations to HMRC — marginal relief and first-year period splits handled. £29 files a dormant year the same way. Compliance Watch is £89 a year if you also want the confirmation statement (its £50 government fee included) and a reminder before every deadline. The price shown is the price you pay — no VAT is added at checkout (we're not VAT-registered), unlike rivals' plus-VAT stickers.
Which companies can file with WrenTax?
Most UK companies, since the 2025 threshold uplift: micro-entity means turnover up to £1m, balance sheet up to £500k, and up to 10 employees. We deliberately don't handle R&D claims, director's-loan charges (CT600A), group structures, loss reliefs or investment property — if that's you, an accountant is the right answer and we'll say so before you pay, not after.
What if HMRC or Companies House rejects my filing?
You see the actual reason — a wrong UTR, a Gateway not enrolled for Corporation Tax — in plain English, and resubmit with every field already prefilled, free. If a filing can't be made acceptable at all, we refund the fee in full. Nothing is registered and you're never charged twice for the same year.
Do I still need an accountant?
For a dormant company, or a simple trading company with straightforward income, accurate software is genuinely enough — that's exactly the case we built for. Complexity — payroll, R&D, property, groups — is where an accountant earns their fee. We do the mechanical half properly; we don't pretend to replace judgement.
Is checking my company really free?
Yes — completely. Look up any UK company by number and see every statutory deadline, straight from the register, with no account and no email. You can even subscribe to the deadlines as an iCal feed.
Who is behind WrenTax?
A UK company you can look up with our own tool: WrenTax is operated by UniBookTrade Ltd, company number 17019570, registered in England & Wales. It's built by a founder who files these returns himself, in the open — every filing engine claim on this page is backed by an acceptance receipt from the registers' own systems.
See every deadline your company has — free, in about ten seconds.
Deadlines and prefill come straight from Companies House. Corporation tax dates are clearly marked as estimates. Subscribe to any company's deadlines as an iCal feed — no account needed.