An accountant for Companies House and HMRC filings, not just one of them
A UK limited company doesn't file once. It has two separate filing relationships to keep straight, one with Companies House and one with HMRC, each with its own deadline and its own document. Founders searching for an accountant who handles both are usually trying to solve for the whole thing in one relationship, rather than juggling a bookkeeper for one side and a return-only service for the other. Here's what each body actually wants from you, and what to check before you hand it over.
What Companies House actually wants
Companies House gets your statutory annual accounts, filed within 9 months of your company's financial year end (21 months after incorporation for your first set), plus a confirmation statement confirming who owns and runs the company, due at least once every 12 months. Both become public record, searchable by anyone: lenders, landlords, and whoever might buy your business one day.
Miss either deadline and Companies House can issue a late filing penalty automatically, with no warning phone call first. Keep missing them and the company can eventually be struck off the register, which is a separate risk from anything you might owe HMRC.
What HMRC wants, and why it's a different filing
HMRC wants your Corporation Tax return, the CT600, built from the same accounts you sent to Companies House but submitted to HMRC separately, within 12 months of your accounting period ending. The tax itself is due earlier, 9 months and a day after the period ends, so you're often paying before you've filed the return that explains the number.
If you're VAT registered, add quarterly VAT returns on top, each due one month and seven days after the VAT period ends. None of these dates line up with each other, which is exactly why founders running this alone tend to miss one deadline while they're focused on another.
Why the numbers need to match in both places
The accounts filed at Companies House and the accounts behind your CT600 to HMRC should be the same figures, just used for different purposes. When a bookkeeper handles one and a separate return-only service handles the other, small differences creep in: a debtor written off in one set but still sitting on the balance sheet in the other, or a director's loan treated one way in the accounts and another way in the tax computation.
HMRC and Companies House don't cross-check every filing against each other, so a mismatch can sit quietly for years. It tends to surface at the worst moment, in an HMRC enquiry or a buyer's due diligence before an acquisition. One accountant preparing both filings from the same working papers is the simplest way to stop the gap forming in the first place.
What to check before you hand this over
Chartered accountant status means someone passed the ACA and is bound by ICAEW's rules on professional indemnity insurance, ongoing training, and a complaints process you can escalate to if the work goes wrong. Ask directly whether the person filing your accounts holds that qualification, or whether you're paying for a subscription with occasional human sign-off. ICAEW publishes a public register you can check any chartered accountant against, so you don't have to take the claim on trust.
Also worth asking: does this person file both the Companies House accounts and the HMRC return themselves, or do they hand one off to someone else? Software can pull your bank feed, categorise transactions, and draft the numbers fast, but deciding how a director's loan should be treated for tax, or whether an expense is genuinely allowable, still takes a person who knows your company applying judgment to it.
Frequently asked questions
Can I file my own Companies House accounts and skip an accountant?
Yes. Companies House lets a director file accounts directly through its own online service, and plenty of very small companies do exactly that. The catch is that your Corporation Tax return to HMRC still needs the same figures prepared correctly, so if the accounts are wrong you're usually amending both filings, not just one.
What happens if my Companies House accounts and my HMRC Corporation Tax return don't match?
Nothing happens immediately; there's no automatic cross-check between the two systems. The risk shows up later, in an HMRC enquiry, a lender's due diligence, or a buyer's review before a sale, when someone puts both documents side by side and asks why the numbers differ. Working from one set of records behind both filings avoids the question ever coming up.
Do I need a different accountant for VAT than for my annual accounts and Corporation Tax?
No, and splitting them usually costs you more, not less. VAT returns, annual accounts, and the Corporation Tax return all draw from the same underlying bookkeeping, so one accountant working from one set of records can do all three without re-doing reconciliation work that's already been done for a different filing.