Which filing option do I need?
Short version. Choose by what HMRC already has for this accounts period. If HMRC has nothing yet, choose Standard return. If HMRC already has your first CT600 with the full accounts and it is correct, choose File only the remaining CT600. To correct a return filed elsewhere, start from Amend filing made elsewhere.
On this page
New returns and amendmentsWhere you see it: Company Profile & Period › Filing purpose
Filing purpose decides which CT600s for this accounts period are sent, and whether each one is a new return or an amendment.
- Most accounts periods are 12 months or less and need one CT600. Choose Standard return for those.
- An accounts period that ends more than 12 months after it starts needs two CT600s. HMRC may already have one of them, so the options below cover each case.
- Every option uses the dates and figures you enter. Which option matches your filings is for you to decide, yourself or with your accountant.
Match what HMRC already has
| What HMRC already has for this accounts period | Choose | Where |
|---|---|---|
| Nothing yet | Standard return | New filing |
| The first CT600, with the full accounts, and it is correct | File only the remaining CT600 | New filing |
| The first CT600, which needs correcting. The second is not filed | Amend the first CT600 and file the second as new | Amend filing made elsewhere |
| Both CT600s, and they need correcting | Amend both CT600 returns | Amend filing made elsewhere |
| The second CT600 only | File the first return on its own dates, then amend both once HMRC accepts it | Separate CT600 dates |
The most common mistake is choosing File only the remaining CT600 when nothing has been filed. That option files the second return only, and treats the whole year's figures as earned in its short dates, so a full year's profit can be taxed at 25%. See the worked comparison
How to check what HMRC has
Your HMRC business tax account lists the Corporation Tax periods HMRC expects and which returns it has received. A CT603 notice to deliver a return also shows the dates of the period HMRC is asking about. If someone else filed for you, ask them which returns they sent and for which dates.
More help: HMRC business tax account · Matching your two CT600 dates to HMRC · Wrong HMRC Corporation Tax dates
Returns you filed with us
To correct a return you filed with us, open it from the filing page and click Amend this filing →. You do not choose a Filing purpose for that route. How to amend a CT600
Option guides
Each guide says who the option is for, when not to use it, and every field to fill in.
Looking for a different field or step? See all filing wizard guides →