| Date | What’s Due |
| 1 September | Corporation tax for year to 30/11/20 unless pay by quarterly instalments |
| 19 September | PAYE & NIC deductions, and CIS return and tax, for month to 5/9/21 (due 22 September if you pay electronically) |
| 1 October | Corporation tax for year to 31/12/20 unless pay by quarterly instalments |
| 5 October | Deadline for notifying HMRC of chargeability for 2020/21 if not within Self-Assessment and receive income or gains on which tax is due |
| 14 October | Final date for CJRS Furlough grant claims for September 2021 |
| 19 October | PAYE & NIC deductions, and CIS return and tax, for month to 5/10/21 (due 22 October if you pay electronically) |