UK Company First-Year Filing, DIY: £228 All-In + Two Tax Breaks Most Founders Miss

My earlier guide covered the full methodology. This post is the real-world timeline log — I just finished my UK company's entire first-year compliance, completely on my own.

Current status:

✅ Confirmation Statement filed
✅ Annual Accounts filed
⏳ CT600 waiting for the HMRC activation code

Total cost: £228 (agents typically charge £200-400 per filing, and Chinese Taobao agents charge ¥2,000+), 5 weeks of waiting + one afternoon of actual work.

Here is the complete timeline, plus two tax breaks I only learned about after stepping in the holes myself.

The Complete Timeline Checklist

Week 1 · Receive UTR + register Government Gateway

HMRC mails your UTR (Unique Taxpayer Reference) to the registered address (arrives 2-3 weeks after incorporation)
As soon as you have the UTR, register a Government Gateway Organisation account (NOT Agent — that type is for accountants managing clients)
In Gateway, Add Corporation Tax: enter the UTR + a UK contact number
Wait for HMRC to mail the CT activation code (another 7-10 days)

⚠️ Do the ID Check App in parallel: download the Companies House ID Check App (not the Gateway one), scan your passport via NFC + liveness selfie, and get your Personal Code. Mandatory since 2025-11-18 — without it you cannot file the CS01 later.

Month 11 · Start organising the books

Export all currency CSVs from Wise Business (I had 8 currencies)
Convert to GBP using HMRC monthly exchange rates (do not use per-transaction daily rates — that way lies madness)
Map everything into a 17-account Trial Balance template: Sales / Cost of Sales / Admin Expenses / Interest Income / Corporation Tax, etc.

Month 12 · CS01 deadline (hard deadline)

The Confirmation Statement window opens
CS01 fee: £50, paid with a friend's UK card in one go
Renew the Registered Office service at the same time (free first year, £39/year after)

Months 13-20 · File the annual accounts

Buy the TinyTax Bundle (£59), import your Trial Balance
It auto-generates CT600 + Annual Accounts (iXBRL format)
Submit to HMRC + Companies House
Pay Corporation Tax last (hard deadline: accounting period end + 9 months + 1 day)

First-Year Cost Breakdown

Item	Cost	Notes
CS01 (Confirmation Statement)	£50	Friend's UK card
TinyTax Bundle	£59	Generates CT600 + Accounts
Registered Office renewal	£39	Annual from year 2
Personal Code IDV	£0	App is free
Card payment fees	£0	Bought my friend a coffee
Government Gateway / HMRC filing	£0	Free
Service fees subtotal	£148	Excluding tax
Actual first-year total incl. Corporation Tax	£228	Incl. ~£80 tax

For comparison: agencies charge £200-400 per filing, and many default to filing your company as Dormant. If you have real transactions, a Dormant filing is fraud — HMRC penalties start at £3,000.

Two Tax Breaks Indie Founders Usually Miss

These two saved me thousands of pounds in tax.

1️⃣ Equipment purchases qualify for AIA — 100% deductible in year one

AIA = Annual Investment Allowance.

Computers, monitors, cameras, servers — capital equipment bought by the company can be deducted 100% against profit in the year of purchase via AIA
No multi-year depreciation needed: buy this year, deduct this year
Annual cap: £1,000,000 (an indie founder will never hit it)

My case: the MacBook + monitor + filming gear my company bought in year one all went through AIA, knocking thousands of pounds off taxable profit.

2️⃣ Put every subscription on the company card with a company invoice

ChatGPT Plus, Claude Pro, Cursor, Notion, domains, cloud services…
Pay all of them with the company card, invoice in the company name
They are all 100% deductible as Admin Expenses
After year one, my company owes me €2,465.94 (subscriptions + equipment I paid personally) — I can withdraw this from future profits without paying personal income tax

💡 Set up the company card early: every AI tool subscription paid from the company account accumulates automatically into deductible expenses — no year-end statement archaeology.

Pitfalls I Hit (So You Don't Have To)

Choose Organisation in Government Gateway — choosing Agent means re-registering
The ID Check App is slower than you think: NFC passport positioning is finicky, took me 5 attempts. Do it early
ARD defaults to 13 months: your first accounting period is 13 months, not 12. To align it, file an AA01 within year one
Export ALL Wise currencies: USD/EUR/HKD are separate accounts. Exporting only GBP means under-reporting income — that gets penalised
There is no "personal allowance" for companies: the £12,570 allowance is for personal income tax. Companies pay 19% from the first pound of profit
Registered Office starts charging in year 2: set a calendar reminder — if it lapses, you stop receiving all HMRC mail

FAQ

How much does it cost to file UK company accounts yourself?

Service fees are £148 (CS01 £50 + TinyTax £59 + Registered Office renewal £39). Adding a small company's Corporation Tax, my actual first-year total was about £228. Agencies charge £200-400 per filing and often default to Dormant status — which is fraud if you have real transactions, with HMRC penalties starting at £3,000.

How long does first-year UK company compliance take?

About 5 weeks of waiting plus one afternoon of actual work. The waiting is mostly HMRC mailing the UTR (2-3 weeks) and the CT activation code (7-10 days), so register your Government Gateway account as soon as the UTR arrives to parallelise the waits. Year two takes half an afternoon.

Does a UK company with no revenue still need to file?

Yes. The Confirmation Statement (CS01, £50) is due every year regardless of revenue. Annual Accounts and CT600 must also be filed. A company with zero transactions can file as Dormant, but if there are any real transactions you must file properly — otherwise it is fraud.

How can an indie founder legally reduce UK Corporation Tax?

Two commonly missed deductions: (1) equipment like computers and cameras qualifies for AIA (Annual Investment Allowance) — 100% deductible against profit in the purchase year, capped at £1M; (2) pay every subscription (ChatGPT, Claude, Cursor, domains, cloud) with the company card and a company-name invoice — all fully deductible as Admin Expenses. Personal advances can later be withdrawn from company profits without personal income tax.

One-line Summary

£228 + 5 weeks + one afternoon = a UK company's entire first-year compliance, done solo. The real cost was never money — it's the cognitive friction of doing it the first time. Once you've run the process once, year two takes half an afternoon.

📚 More hands-on logs from an indie founder going global: follow @GoSailGlobal.

⚠️ Disclaimer: This article is a personal experience log shared for information only. It is not tax, legal, or financial advice. For tax matters, refer to official HMRC / Companies House documentation and consult a licensed accountant where necessary.