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HMRC letter codes · Corporation Tax (CT)

CT630Group Payment Arrangements Closure Notice

Last reviewed 14 October 2026 · How Tax Letters checks its facts

In short

GOV.UK says a CT630 is the Notice of closure that HMRC issues to the nominated company (the member that the companies in a Group Payment Arrangement nominate to make payments for all of them) after the arrangement closes for a period, showing the payments made and the Corporation Tax due for each participating company at the date of closure.

“The companies in the arrangement nominate one of the members to make the payments on behalf of all the companies. This is known as the ‘nominated company’. … After the Group Payment Arrangement closes for a period, we will issue ‘Notice of closure’ (form CT630) to the nominated company. This will show the payments made and the Corporation Tax due for each participating company at the date of closure.”

GOV.UK: Group Payment Arrangements for Corporation Tax · checked 14 October 2026

Information, not advice: this page reports what HMRC, GOV.UK and the bodies named publish about CT630. Each fact has its source and the day it was checked beside it.

What it is

HMRC's internal manual forms index describes the CT630 as a notice issued to the nominated company once a tax charge has been established on each participating company's accounting periods in a Group Payment Arrangement, detailing the charges held for each participating company, the payments made for the Group Payment Period and any apparent underpayment or overpayment.

“A notice issued to the nominated company once a tax charge has been established on each of the participating companies APs in a Group Payment Arrangement detailing charges held for each participating company, payments made in respect of the Group Payment Period and any apparent underpayment or overpayment.”

HMRC COTAX Manual: COM150, Forms index · checked 14 October 2026

HMRC's CT630 and CT631 notes say they cover both the Closure Notice (form CT630) and the Apportionment Notice (form CT631).

“These notes cover both the Closure Notice (form CT630) and the Apportionment Notice (form CT631).”

GOV.UK: Group Payment Arrangements: CT630 and CT631 Notes · checked 14 October 2026

What it asks

HMRC's CT630 and CT631 notes say the Closure Notice (form CT630) asks the company to say how it wants to allocate each payment shown between the participating companies. If it does not supply the information within 30 days of the date of the notice, or confirm figures sent earlier, the notes say HMRC will send an Apportionment Notice.

“You need to tell us how you want to allocate each payment shown between the participating companies. … If you don’t supply the information within 30 days of the date of this notice, or confirm the figures that you sent to us before we issued this notice, we’ll send you an Apportionment Notice showing you how we intend to allocate the payments for you.”

GOV.UK: Group Payment Arrangements: CT630 and CT631 Notes · checked 14 October 2026

GOV.UK's Group Payment Arrangements for Corporation Tax guide says the CT630 notice will ask the nominated company to pay any outstanding tax due, or advise how it wants to dispose of any net overpayment.

“The CT630 notice will ask the nominated company to pay any outstanding tax due, or advise how it wants to dispose of any net overpayment.”

GOV.UK: Group Payment Arrangements for Corporation Tax · checked 14 October 2026

Free help and HMRC contacts

For advice about Group Payment Arrangements, including about a CT630, HMRC's advice line (GOV.UK) is 03000 583 947, open Monday to Friday, 9am to 4pm and closed on bank holidays. GOV.UK says to have the Group Payment Arrangement reference number to hand when calling, and has a “Find out about call charges” link.

“Call for advice about Corporation Tax Group Payment Arrangements. Have your Group Payment Arrangement reference number with you when you call. … Telephone: 03000 583 947 Opening times: Monday to Friday: 9am to 4pm. Closed bank holidays … Find out about call charges”

GOV.UK: Corporation Tax Group Payment Arrangements: enquiries · checked 14 October 2026

Free help first

These routes are described by GOV.UK, TaxAid and Citizens Advice themselves.

  • HMRC's extra supportHMRC offers extra support if your health condition or personal circumstances make it difficult to contact HMRC, for example a mental health condition, financial hardship or being treated in hospital.
  • Someone to deal with HMRC for youYou can authorise a friend, relative or voluntary organisation to talk to HMRC for you and help you fill in forms.
  • TaxAidTaxAid helps people with tax problems who cannot pay for advice. Tax Help for Older People merged with TaxAid in July 2025.
  • Citizens AdviceCitizens Advice gives confidential advice online, over the phone and in person, for free.