Key Dates: January 2022 1 JanuaryThe third and final stage of the post-Brexit import Core Model begins. This will require businesses to undertake full customs checks. 7 JanuaryVAT returns and payments due for Accounting Quarter period ending 30 November. 22 JanuaryDeadline for electronic remittance of PAYE, NICs and CIS to HMRC. 31 January Deadline for paying Self-Assessment balancing payment and capital gains tax for tax year ended 5 April 2021. Deadline for the first payment on Self-Assessment account for 2021/22. Final online deadline for Self-Assessment tax return. Deadline for filing of accounts with Companies House for accounting periods ended 31 January 2021.