Fergus WatsonR&D Senior Financial Consultantt

As our finance guru, Fergus also provides financial training to the rest of the team and supports our internal finance operations.

As tax claims, all R&D claims, of all types, require adjustments to be made to the CT600 in order to correctly file an R&D claim with HMRC. This can be done as part of the original return or through an amendment to the original.

What is a CT600?

A CT600 is the standard HMRC-issue form which is a part of a Company Tax Return; Limited companies use the CT600 to calculate the corporation tax, including any tax amendments, that they owe – it is a fundamental element of a company’s R&D claim.

Amending your CT600 for R&D claims

Whilst making an R&D claim which simply reduces your CT liability is fairly straightforward, requiring only minimal changes and input within the tax return, new legislation has been brought in for RDEC claims and payable tax credits to SMEs.

Companies claiming R&D tax credits must now also complete a new supplementary CT600L form. Without this information being correctly filled in, your R&D claim will be automatically rejected by HMRC. If your claim is submitted close to the end of your financial year this is particularly important: confirmation of the rejection may not be received for several months after filing.

Whilst most tax software will assist with the preparation of the CT600L, the accurate preparation of an R&D claim still requires a detailed knowledge of the process in order to ensure the claim is filed correctly.

SME scheme and CT600L

For claiming the SME tax credit, there are a few key considerations:

  • Information on the SME PAYE/NIC cap must be provided as part of the return, including if the exemption is applicable.
  • You must also state whether the credit is being used to discharge any other liabilities on the return.

RDEC scheme and CT600L

If claiming under the RDEC scheme, a CT600L must always be completed – the 7 steps as part of the RDEC payment mechanism must be completed. You can read more about the RDEC 7 steps here.