File two CT600s for a first accounting period over 12 months
Taxley splits a first accounting period longer than 12 months into two Corporation Tax accounting periods and files both CT600 returns to HMRC, from one set of accounts and for one fee. The accounts can cover up to 18 months. Taxley doesn't split a charity's long period, and it can't carry a trading loss back from one.
Preparing and previewing is free. One fee covers both returns, and you pay only when you choose to file.
Last reviewed
What can't Taxley do with a long first accounting period?
A few long periods are outside what Taxley files today.
- Accounts longer than 18 months. A period of account can't be longer than 18 months, so Taxley won't start a return for one.
- Charities. Taxley doesn't file a charity's period of account over 12 months.
- Carrying a loss back. Taxley can't carry a trading loss back from a period of account longer than 12 months. It can carry the loss forward instead.
- Some first accounts at Companies House. A company's first accounts must start on the date of incorporation. The accounts can start before the first return does, so set them to start on that date before you pay. If they start later, Taxley files the CT600s only and you file the first accounts there yourself; the filing page gives the deadline.
- Older periods. Accounting periods that started before 1 April 2020.
- Advice. Taxley is software from Taxley UK LLP, not an accountant or tax agent. The directors stay responsible for the figures.
How does Taxley file two CT600s for a first accounting period over 12 months?
You enter the period once and Taxley builds both returns. A Corporation Tax accounting period can't be longer than 12 months, so the first return covers the first 12 months and the second covers the rest (GOV.UK: your limited company's first accounts and Company Tax Return).
- Start a return with the accounts dates. Find the company on the Companies House register and enter the whole period the accounts cover. Taxley sees that it's longer than 12 months.
- Enter the figures for the whole period. Income, expenses and the balance sheet, as they are in the accounts.
- Check the two returns. Taxley splits income and expenses between the two periods by days and works out the tax for each. You see both CT600s, the computation and the accounts before you pay.
- Pay once and file. Taxley sends both returns to HMRC together, with the company's own Government Gateway login, and tells HMRC you're making more than one return.
- File the accounts at Companies House. Once the return is paid and finished, Taxley files the one set of accounts there. You need the company's 6-character authentication code.
The free long accounting period calculator shows the same split and both sets of dates before you start.
When are the two returns and the tax due?
Both CT600s are due 12 months after the end of the accounts period, but each period's tax has its own payment date: 9 months and 1 day after that period ends. So the tax for the first 12 months is due first. The free Corporation Tax deadline calculator gives every date for your period. Taxley works out the tax for each period; it doesn't pay it for you.
What does it cost to file two CT600s with Taxley?
One fee covers both returns: £49.95 with micro-entity accounts or £129 with small-company accounts. It also covers filing the accounts at Companies House. There's no subscription. Every plan is on the pricing page.
Frequently asked questions
Do I pay twice for the two CT600 returns?
No. A period of account longer than 12 months is one return in Taxley, so you pay one fee and Taxley files both CT600s to HMRC together. The fee also covers filing the accounts at Companies House.
How does Taxley split the profit between the two periods?
It splits income and expenses between the first 12 months and the rest of the period by the number of days in each, then works out the tax for each period separately. You see both returns before you pay.
Is the second, shorter return a nil return?
Not usually. It covers the rest of the accounts period, so it carries that period's share of the profit and its own tax. Taxley files it as a full return.
Does this only work for a company's first accounts?
No. Taxley splits any period of account longer than 12 months, up to 18 months, for example after the company extends its year end. The same limits apply.
Are there two Companies House filings as well?
No. There's one set of accounts for the whole period, and Taxley files it at Companies House once the return is paid and finished.
Ready to file both returns?
Enter the whole period once. Taxley builds both CT600s, and you pay only when you file.