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If this is your client’s first time claiming R&D tax credits (or they have not claimed in the last three years), they have to notify HMRC within six months of their year-end.
What does this mean?
If your client has a financial year-end in June 2025, the Advanced Notification Form (ANF) deadline is December 31, 2025 – it will be here before you know it!
Even if your client has conducted legitimate R&D activities, failure to submit the ANF when required will invalidate the claim.
ANF deadlines in 2025/26
Here are the deadlines to notify HMRC about your client’s intention to claim R&D tax relief:
| Accounting year-end | Deadline |
| 30 June 2025 | 31 December 2025 |
| 31 July 2025 | 31 January 2026 |
| 31 August 2025 | 28 February 2026 |
| 30 September 2025 | 31 March 2026 |
| 31 October 2025 | 30 April 2026 |
| 30 November 2025 | 31 May 2026 |
| 31 December 2025 | 30 June 2026 |
| 31 January 2026 | 31 July 2026 |
| 28 February 2026 | 31 August 2026 |
Don’t miss your client’s ANF deadline! Contact our team today for expert R&D support.
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