Changes and issues affecting the Corporation Tax online service

Service

Check issues

Electricity Generator Levy (EGL)

There are currently no boxes available on the Company Tax Return (CT600) for you to submit:

• Electricity Generator Levy receipts

• the levy amounts payable

These will be updated on the return in April 2024.

If you need to tell us about Electricity Generator Levy receipts and the amount of levy payable before April 2024, use:

• box 986 — Energy (Oil and Gas) Profits Levy (EOGPL) amounts liable

• box 501 — EOGPL payable

Completing CT600N Residential Property Developer Tax (RPDT) and claiming RPDT group relief for carried forward losses

HMRC is aware of an online filing issue due to a restriction within the Corporation Tax online service.

You will only be affected if both the following apply:

• you are completing Section 3 Part 3 — claims to RPDT group relief for carried forward losses on supplementary page CT600N
• you do not have a simplified arrangement in place, so you must attach notices of consent

The service will be updated in April 2024 to fix this issue. If you need to file your return before this date, contact your Customer Compliance Manager.

Full expensing and 50% first-year allowances

As announced at Spring Budget 2023, companies incurring qualifying expenditure on plant or machinery on or after 1 April 2023, but before 1 April 2026 can claim:

• a 100% first-year allowance for main rate expenditure — this is known as full expensing
• a 50% first-year allowance for special rate expenditure

Find out more about full expensing.

The HMRC Corporation Tax online service will not be updated to support full expensing until April 2024. If you do not need to report this new relief, you can file online in the normal way before the Corporation Tax online service is updated.

If you need to submit either a full expensing or 50% first-year allowance claim, or both or report a balancing charge online before April 2024, you can do this using existing capital allowances boxes on the CT600.

For full expensing:

• boxes 725 and 750 should be used for claim amounts
• boxes 730 and 755 should be used to report balancing charges
• box 760 should be used for qualifying expenditure

You should do this until the online service has been updated and new boxes are available.

For the 50% first-year allowance:

• boxes 693 and 743 should be used for claim amounts
• boxes 694 and 744 should be used to report balancing charges
• box 773 should be used for qualifying expenditure

New boxes will not be added for the 50% first-year allowance and the CT600 guide will be amended soon. These boxes should continue to be used once the online service has been updated.

You will not be able to claim full expensing or the 50% first-year allowance using the HMRC free filing service (Company Accounts and Tax Online (CATO)) — this service will not be updated to allow these claims.

Research and Development expenditure credit (RDEC) claims

HMRC introduced the additional information form on 8 August 2023. This must be submitted for all claims for Research and Development (R&D) tax relief or expenditure credit.

We are aware that customers are unable to complete both boxes 655 and 657 on the CT600 and may get the following error:

If you get this error, do not make entries in boxes 655 and 657.

You must still submit the additional information form to make a valid R&D expenditure credit claim.

We will update the service in April 2024 to fix this issue.