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Tax news in brief

Author: ICAEW Insights

Published: 27 Jan 2026

Highlights from the broader tax news for the week ending 27 January 2026, including: how to make correct use of the agent dedicated line; and guidance from HMRC on the CT600 and the new 40% first year allowance (FYA).

The agent dedicated line

HMRC has asked us to remind members that agents should not use the self-assessment (SA) reactivation option (option 1) on the agent dedicated line (ADL) for general SA queries. The SA reactivation option is for SA reactivations only. HMRC says that its “advisers are unable to address any other SA enquiries via this route [the reactivation option] and are also unable to transfer the agent to the general enquires line”.

New 40% FYA

HMRC has updated its guidance on issues that may affect how to file a company tax return to include the new 40% FYA announced at the Autumn Budget 2025. HMRC says that it will update the corporation tax online service in April 2027 for the new FYA. To claim relief before then, the following boxes on form CT600 should be used:

  • boxes 725 or 750 for claim amounts; and
  • box 760 for qualifying expenditure.

Further information

Budget changes to capital allowances | ICAEW

R&D tax relief

HMRC is warning companies in the advertising sector  who may be encouraged to make claims for research and development (R&D) tax relief by third parties that they may not be eligible to claim the relief. The letter explains why this is likely to be the case and the consequences for the company of making a claim that is found to be incorrect.

Tax Faculty

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