What year-end actually is

The 14 April phone call

A director we worked with rang her accountant on the morning of 14 April. The conversation went: "I've just realised our year-end was 31 March. The books are a mess. Can you sort it?". The accountant could — for a fee — but only once she'd handed over a usable set of records. What followed was a six-week scramble: a bookkeeper working evenings, a backlog of three months of un-coded card transactions, two missing supplier statements, and a frantic round of customer calls trying to remember which invoices had actually been paid in cash at Christmas.

The accountant's bill came in at three times the previous year. Not because the work was harder, but because the work was unpicking before it was recording. The director paid it. She has not been late since.

The alternative is unspectacular. It's a four-week window before year-end where you walk through a checklist, post the journals the engine prepares for you, lock the period, and file the final VAT return. The accountant gets a clean trial balance. The statutory accounts get filed without drama. Corporation tax gets paid from a number you already knew.

This chapter is the map of that checklist. The five chapters that follow are the territory.

What "year-end" actually means

Year-end is the date your accounting period ends. Not a tax-system date, not a calendar deadline — the date you (or more precisely, the date Companies House holds on file for your company) chose when the company was formed.

The default for a UK limited company is the end of the month exactly twelve months after incorporation. Incorporated on 14 March 2024? Your default year-end is 31 March 2025, and then 31 March every year after. You can change it once in a five-year window using form AA01 — most owner-managers shift their year-end to 31 March or 31 December to align with personal tax or natural seasonal cycles.

The accounting period is what the year-end closes. The accounting period is the unit of measure for nearly every statutory filing: statutory accounts, the corporation tax computation, the CT600 return, dividend declarations, depreciation policies. When this chapter says "the year", it means your year — the twelve months running up to your year-end, whatever date that is.

Key point: Year-end is not 5 April (that's the personal tax year, only relevant to your Self Assessment) and it's not 31 March (that's the default but you may have chosen something else). Check your year-end on Companies House if you're not sure — it's on your company's overview page, labelled "next accounts made up to".

Why this matters even if you have an accountant

The most common misconception about year-end is that it's the accountant's problem. They prepare the statutory accounts and the CT600 — yes. They file them — yes. They give you a number for corporation tax — yes.

But they do all of that from your books. If your trial balance going into year-end is wrong, the accounts they prepare are wrong, and you'll either pay them to fix it (billable hours, on the clock) or you'll file something inaccurate that needs correcting later (worse). Trash in, trash out, then more invoices to clean up the trash.

The job of the owner-manager at year-end isn't to prepare the accounts. It's to hand over clean books. The five chapters in this series cover the operational tasks that turn your live, in-progress books into a clean trial balance: write off the bad debts, claim back the VAT on them, sign off depreciation on fixed assets, lock the period so no-one back-dates a journal, and file the final VAT return.

Do those five things and the handover to your accountant takes a phone call, not a fortnight.

The five chapters in this series

#	Chapter	What it does
2	Bad-debt review — specific and general	Write off doubtful debts before they pollute next year's P&L
3	VAT bad-debt relief — HMRC's 6-month rule	Reclaim VAT on bills that won't ever be paid
4	Fixed Asset Register sign-off	Confirm depreciation policies and post the year's charges
5	Period lock	Close the books so no-one back-dates a journal into a closed year
6	MTD VAT — the final return	Submit your last VAT return of the year through Making Tax Digital

The order matters. Bad-debt comes first because raising specific provisions changes your AR numbers, and your AR numbers feed the general provision. The general provision in turn affects your debtor balance on the balance sheet. Then VAT bad-debt relief comes next, because it's triggered by the specific provisions you just raised — the engine auto-fires the relief claim on any provision where the 6-month rule passes.

Fixed Assets comes next, because depreciation journals affect P&L and balance sheet but don't interact with AR. Period lock comes second-to-last because it freezes everything you've done above. And MTD VAT comes last because it consumes the locked numbers and ships them to HMRC.

If you do them out of order, you'll either re-run calculations (annoying) or post into a locked period (impossible — the engine refuses) or claim VAT relief on a debt you later un-provision (mess). In order, each chapter consumes what the previous one produced.

What year-end is NOT

It's not when corporation tax is due. Corporation tax is payable 9 months and 1 day after year-end. So if your year-end is 31 March 2026, your corporation tax is due 1 January 2027. You have nine months to compute it and pay it. Year-end itself just freezes the numbers you'll be computing it from.

It's not when statutory accounts are filed at Companies House. Accounts are due 9 months after year-end. Same rule, different document. You file the accounts before the corporation tax is paid (usually) because the accounts inform the tax computation.

It's not when you have to pay a dividend. Dividends can be declared and paid at any point — but year-end is a common point for an owner-manager to take a top-up bonus dividend, because by then you know the profit number and you know what's left after tax. Year-end isn't a deadline for dividends; it's a useful informational moment.

It's not when VAT is filed. VAT continues quarterly regardless of your year-end. Your year-end might fall mid-quarter (and usually does). The final VAT return of your accounting period is the one Chapter 6 covers — it's the last quarterly return that closes inside your year, not a year-end-specific event.

What's out of scope of this series

A handful of things happen around year-end that this series deliberately doesn't cover:

• Payroll year-end. P60s for every employee, P11Ds for benefits in kind, the final FPS and EPS submissions to HMRC. Lives in Blankitt HR — see the HR Year-End guide.
• R&D tax credit claims. If you spent money on qualifying R&D activity, you can claim a corporation tax credit. The claim sits inside the CT600 your accountant prepares, not as a separate year-end task in Finance.
• EMI option valuations, EIS / SEIS paperwork. If you've issued share options or taken in tax-advantaged investment, there are statutory deadlines that often (but not always) align with year-end. Talk to your accountant.
• Annual confirmation statement. A separate Companies House filing, due on the anniversary of company formation — not year-end. Often muddled with statutory accounts; they're different forms with different deadlines.

These are real tasks but they belong to other workflows. This series stays inside Finance Business.

What you need handy before you start

Year-end isn't the time to discover three months of un-coded card transactions. Before you open the bad-debt review in Chapter 2, the following should all be true:

• Bank reconciliation is up to date — every line on every account is matched to a bill, an invoice, or an internal transfer.
• All sales invoices for the period are raised — no "I'll bill them next month" hanging in your head from June.
• All supplier bills are entered — including any sat in your email as PDFs that haven't been uploaded.
• Expense claims are submitted and approved — no shoebox of January receipts pending categorisation.
• Payroll is posted for the final month — the wage journal, PAYE/NIC liabilities, and net pay all booked.
• Any deferred income or accruals you usually adjust at month-end have been posted for the final month.

If any of those aren't true, do them before you start the year-end checklist. The chapters that follow assume your trial balance reflects every transaction up to year-end.

When to start

Four to six weeks before year-end is comfortable. You'll have time to chase the customer who hasn't paid invoice INV-0428 (the one you might provision), get the bank-rec finished, and run the general provision a couple of times to settle on the right percentages.

One week before is doable if your books are otherwise clean. You'll feel rushed but you won't miss anything material.

Day-of is a panic. You'll either skip the bad-debt review (and post into next year's P&L), file the VAT return without the relief claim (and lose the VAT you're entitled to recover), or call your accountant in tears.

Block the time. Year-end takes maybe four hours of focused work spread across two evenings if your books are already clean. Make a calendar event for two weeks before your year-end date with the title "Year-end checklist — bad-debt review". Future you will be grateful.

Up next

Chapter 2 is the bad-debt review. We'll walk the aged-debtors list together, raise specific provisions for the debts that won't be collected, and configure a general provision policy for the statistical baseline. By the end of it, your AR balance will reflect what you actually expect to recover — not what you originally invoiced.