About DormantFile

Why DormantFile exists

Our founder built DormantFile out of necessity. He runs several dormant limited companies in the UK — holding structures, side projects that never launched, companies kept open for future plans. Every year, each one needs the same two filings:

• Annual accounts to Companies House
• A nil CT600 Corporation Tax return to HMRC

The companies do nothing, but the paperwork never stops.

For years, the free HMRC tool (CATO) handled the tax return side. It wasn't pretty, but it worked and it cost nothing. When HMRC announced CATO was closing — it closed on 31 March 2026 — the alternatives were bleak: hire an accountant at £80–£300 per company per year for a zero-activity filing, or buy general-purpose accounting software that's overkill for a company with no transactions.

Neither option made sense. So we built DormantFile.

What DormantFile does

DormantFile handles the two filings a dormant or non-trading UK limited company needs each year:

• Annual accounts — prepared and submitted directly to Companies House via their official software filing API.
• Nil CT600 Corporation Tax return — prepared and submitted directly to HMRC via their GovTalk API.

If your company is genuinely dormant — no significant accounting transactions — we file dormant accounts confirming exactly that. If it's not trading but has a transaction or two on its books, most often a Bounce Back Loan it's repaying, it can't file as dormant; we file FRS 105 micro-entity accounts instead, with a short balance sheet showing the loan. Either way the CT600 is nil — no trading profit, no tax liability. DormantFile handles the XML, the submission, and the confirmation — you just review and click submit.

Since August 2026 we also file dormant LLP accounts — and, when HMRC issues a notice to file, the nil SA800 partnership return too. An LLP works the same way with two differences: a designated member approves the accounts rather than a director, and there's no Corporation Tax leg — an LLP is tax-transparent, so any HMRC return is the SA800 instead, due only for years HMRC issues a notice to file. If one arrives, DormantFile files the nil SA800 once Self Assessment is enabled in Settings — members confirmed, statement included — or an accountant can ask HMRC to withdraw the notice instead. We still file dormant LLP accounts only; trading and micro-entity LLP accounts remain an accountant's job.

Also since August 2026, we file the nil Company Tax Return for community interest companies. There is no CIC-specific box on the CT600, so a CIC's return goes to HMRC exactly like any other company's. A CIC's accounts are a different matter, and we say so plainly: Companies House will only take them alongside a CIC34 community interest report and a £15 fee, by post or through its own CIC service — no filing software, ours or anyone else's, can send that package. We file the tax return, track both deadlines, and point you at the right route for the accounts rather than pretending we cover them.

We also send email reminders at 90, 30, 14, 7, 3, and 1 days before your accounts and confirmation statement deadlines, so a deadline never sneaks up on you.

Who we are

DormantFile is built and run by a solo founder based in the UK. He's a software engineer, not an accountant. DormantFile is software — it prepares and submits your filings, but it does not provide accounting or tax advice. If your company is actively trading, or you're unsure which type of accounts it should file, you should speak to a qualified accountant.

We focus on companies and LLPs that aren't trading — whether genuinely dormant, or non-trading with something like a Bounce Back Loan on the books. If your company is trading, DormantFile is not the right tool for you.

Our approach

• Affordable — from £19/year, because filing a nil return shouldn't cost more than the company earns (which is nothing). See our pricing for details.
• Secure — your HMRC credentials are used once to submit your filing and then discarded. We never store them. Your Companies House authentication code is stored only if you choose to save it — encrypted at rest (AES-256-GCM) and never logged. You can see whether it is stored and remove it any time from the company's settings. Read our security page for the full details.
• Simple — no features you don't need. No invoicing, no payroll, no VAT. Just the two filings a dormant or non-trading company actually requires. See how it works for a walkthrough.