UK Annual Accounts & Corporation Tax

Run your year-end on a single calendar.

Annual accounts, Corporation Tax and the CT600 are connected, but they aren't the same filing: they go to different bodies and can have different deadlines. We plan your year-end around these distinctions.

Plan Your Annual Filings Review My Company

01Companies House & HMRC

Two bodies, two separate annual processes.

Companies House

Company information and annual accounts

The registrar of companies. Annual accounts and company details go on the register; these filings aren't tax returns.

Each year

Annual accounts
Confirmation statement

Not

A Corporation Tax return
A tax payment

UK Company Formation

HMRC

Corporation Tax and the tax return

The tax authority. Taxable profit is calculated, the CT600 is filed with the company accounts, and the tax is paid within its own deadline.

Each year

Corporation Tax calculation
CT600 (Company Tax Return)
Corporation Tax payment

Also

Tax and accounting records
VAT returns, if VAT-registered

UK VAT & EORI

02Calendar

Four obligations, four separate deadlines.

These are general rules. First years, period changes and special cases can produce different dates.

Four obligations, four separate deadlines.
	AAAnnual accounts	CT600Company Tax Return	CTCorporation Tax payment	CSConfirmation statement
Body	Companies House	HMRC	HMRC	Companies House
What it is	The company's annual financial accounts	The Corporation Tax return and tax calculation	Paying the Corporation Tax calculated	Confirms company details; not a tax return
General deadline	9 months after the accounting reference date (private company)	12 months after the end of the accounting period	Usually 9 months and 1 day after the end of the accounting period	At least every 12 months, even if nothing changed
First year	21 months from incorporation or 3 months from the accounting reference date, whichever is longer	If the first accounts exceed 12 months, two CT600s are needed	A separate deadline for each tax period	A first review period set by the incorporation date
If late	A Companies House penalty that rises with the delay	Fixed penalties; further penalties on estimated tax if the delay continues	Late-payment interest	A legal duty; prolonged failure can lead to the company being struck off

Body

AACompanies House

CT600HMRC

CTHMRC

CSCompanies House

What it is

AAThe company's annual financial accounts

CT600The Corporation Tax return and tax calculation

CTPaying the Corporation Tax calculated

CSConfirms company details; not a tax return

General deadline

AA9 months after the accounting reference date (private company)

CT60012 months after the end of the accounting period

CTUsually 9 months and 1 day after the end of the accounting period

CSAt least every 12 months, even if nothing changed

First year

AA21 months from incorporation or 3 months from the accounting reference date, whichever is longer

CT600If the first accounts exceed 12 months, two CT600s are needed

CTA separate deadline for each tax period

CSA first review period set by the incorporation date

If late

AAA Companies House penalty that rises with the delay

CT600Fixed penalties; further penalties on estimated tax if the delay continues

CTLate-payment interest

CSA legal duty; prolonged failure can lead to the company being struck off

A general framework. Companies with higher profits pay Corporation Tax in instalments, and exact dates are confirmed for each company's accounting period. This is not tax advice.

03First year

A new company's first period works differently.

A new company's first accounting reference date is the last day of the month in which the anniversary of incorporation falls, so the first accounts period can be longer than 12 months.

A Corporation Tax accounting period can't be longer than 12 months and usually starts when the company starts doing business. If the first accounts cover more than 12 months, two CT600s are filed for the same accounts, and payment dates follow the two separate periods.

Each first-year calendar is company-specific; the incorporation date, the start of business and the accounting reference date are assessed together.

Starting point

Incorporation

Registered at Companies House

01Accounting reference dateLast day of the month of the incorporation anniversary.
02First accounts periodCan exceed 12 months; extensions are limited.
03Corporation Tax periodsUp to 12 months; two periods if needed.
04First annual accounts21 months from incorporation or 3 months from the reference date.
05CT600 & paymentSeparate deadlines for each tax period.

IncorporationFirst-year calendar

04From records to accounts

Year-end starts with the records kept during the year.

An Amazon payout isn't sales revenue: sales, refunds, fees and adjustments are recorded separately. We cover ongoing bookkeeping on our Accounting & Tax page.

Source records

Marketplace reports
Bank statements
Invoices and expenses
Stock records
Payment provider statements

Reconciliation & year-end

Year-end outputs

Annual accounts
Tax calculation
CT600
Corporation Tax payable (if any)

CT600

A return can be due even with no tax to pay.

The CT600 is the company's Corporation Tax return, filed with HMRC together with the tax calculation and the company accounts. According to HMRC, you must still send a return if the company makes a loss or has no Corporation Tax to pay. Filing the return and paying the tax are separate steps.

Filed with the return

Company accounts
Tax calculation
Tax period

Profit ≠ taxable profit

Tax isn't based on the profit in the accounts.

Corporation Tax is worked out on taxable profit, adjusted under tax rules, not on the profit shown in the annual accounts. The rate and reliefs that apply vary by company.

What decides it

Accounting profit
Tax adjustments
Applicable rate
Payment date

05Dormant companies

Dormant doesn't mean nothing to file.

Dormant is defined separately for Companies House and for Corporation Tax; a company can be dormant for one and be treated differently by the other. Having no sales isn't enough on its own.

Dormancy is assessed on the company's transactions for the period, and separately for each body.

For Companies House
No significant accounting transactions in the financial year. Companies House fees, late filing penalties and money paid for shares at incorporation don't count.
For Corporation Tax
Usually when the company has stopped trading and has no other income, such as investments.
Dormant accounts
Companies that are both dormant and small can file dormant accounts with Companies House.
Confirmation statement
Dormant companies still file a confirmation statement.
Telling HMRC
You can tell HMRC the company is dormant; if a notice to file has been issued, a return is still filed.
Transactions
Even without sales, payments, expenses or other income can change the company's position.

06Micro-entity & small

The company's size shapes its accounts.

A company is a micro-entity if it meets at least two of these: turnover of £1 million or less, £500,000 or less on its balance sheet, and 10 employees or fewer. Micro-entities can prepare simpler accounts and send Companies House a balance sheet with less information.

The small company limits are £15 million turnover, £7.5 million on the balance sheet and 50 employees (any two). Eligibility follows statutory criteria; these options affect the accounts filed at Companies House, while accounts for HMRC and members are considered separately.

From 1 April 2028

Accounts must be filed using commercial software
The abridged accounts option will be removed
Small and micro companies will file a profit and loss account, with an option not to publish it
Limits on how often the accounting period can be shortened

Related processes

VAT runs on its own return cycle.

If the company is VAT-registered, VAT returns follow their own periodic calendar, separate from the annual accounts, and rely on accurate records. We cover VAT registration, returns and Making Tax Digital on our UK VAT & EORI page.

Accounting: Accounting & Tax
VAT: UK VAT & EORI
Company: UK Company Formation

To get started

What information do we need for year-end?

The information requested can vary with the company's period, activity and the scope of the service.

Company number and incorporation date
Accounting reference date
Previous accounts and returns
Marketplace and bank records
Invoices and expense documents
Stock information — if any
HMRC and Companies House letters
VAT status

Process

From accounting period to payment.

01Periods and deadlines
02Gathering records
03Reconciliation
04Annual accounts
05Tax calculation
06CT600
07Payment timing
08Ongoing duties

Service scope

From records to returns: the year-end process.

Scope is defined around your needs; not every module is needed for every company.

Define the Scope Together

Year-end & filing

Year-end records review
Marketplace and bank reconciliation
Annual accounts preparation
Corporation Tax calculation
CT600 preparation and filing support

Compliance & special cases

Dormant accounts support
Confirmation statement support
Past periods — Depending on scope
Annual compliance coordination

Transparency

We prepare and track the process. We don't guarantee tax outcomes.

We support the preparation of annual accounts and returns; the tax position depends on the company's transactions and the law. Companies House and HMRC deadlines, rules and fees can change, and the current position is confirmed for each period. This information is general and is not individual tax advice.

Frequently Asked Questions

About UK annual accounts

See all questions

Are annual accounts and the CT600 the same document?

No. Annual accounts are the company's yearly financial accounts, filed with Companies House. The CT600 is the Corporation Tax return, filed with HMRC together with the tax calculation and the company accounts. Paying the tax has its own deadline as well.

When are a company's first accounts due?

For a private company, the first accounts are due at Companies House within 21 months of incorporation or 3 months from the accounting reference date, whichever is longer. After that, the deadline is 9 months from the accounting reference date.

Are the CT600 and the Corporation Tax payment due on the same date?

No. The CT600 is due 12 months after the end of the accounting period, while Corporation Tax is usually due earlier: 9 months and 1 day after the end of the period. Companies with higher profits pay in instalments.

What if my first accounts cover more than 12 months?

A Corporation Tax accounting period can't be longer than 12 months, so first accounts covering more than 12 months need two CT600s, each with its own filing and payment dates.

What is a dormant company?

For Companies House, a company is dormant if it had no significant accounting transactions in the financial year; filing fees, late filing penalties and money paid for shares at incorporation don't count. For Corporation Tax, a company is usually dormant when it has stopped trading and has no other income. The two definitions aren't the same.

Does a dormant company still file accounts?

Yes. Dormant companies still file annual accounts with Companies House. Companies that are both dormant and small can file simpler dormant accounts and don't need an auditor's report.

Does a dormant company file a confirmation statement?

Yes. A confirmation statement is filed with Companies House at least every 12 months, whether or not the company is dormant. It isn't a tax return.

If I made no sales, is my company dormant?

Not necessarily. Even without sales, payments, expenses, investment income or other transactions can mean the company isn't dormant for Companies House or for Corporation Tax. It depends on the transactions in the period.

What are micro-entity accounts?

A company that meets at least two of these, turnover of £1 million or less, £500,000 or less on its balance sheet and 10 employees or fewer, is a micro-entity. It can prepare simpler accounts and send Companies House a balance sheet with less information.

What changes are coming to accounts filing?

According to Companies House, from 1 April 2028 accounts must be filed using commercial software, the abridged accounts option will be removed, and small and micro companies will also file a profit and loss account, with an option not to publish it. We follow the official sources for dates and detail.

What happens if accounts or the CT600 are late?

Companies House charges private companies £150 to £1,500 for late accounts depending on the delay, doubled if accounts are late two years in a row. HMRC charges fixed penalties for a late CT600 and further penalties based on estimated tax if the delay continues, and charges interest on late payment.

Do VAT returns follow the same deadline as the annual accounts?

No. VAT-registered companies file VAT returns on their own periodic calendar, separate from the annual accounts and the CT600. We cover VAT on our UK VAT & EORI page.

UK Annual Accounts

Let's map out your year-end calendar.

Share your company details and accounting period, and we'll plan which filings are due and when.