SolvedARTG4240 | Review of direct and indirect taxes decisions: Arranging for a review: Time limit for customer to accept HMRC's offer of review
From HM Revenue & Customs · Appeals reviews and tribunals guidance
If the customer disagrees with HMRC’s decision they should either
accept HMRC’s offer of a review, or
appeal to the tribunal
within 30 days of the date shown on the letter offering a review.