Key Dates and Deadlines for the Final Quarter of the UK Financial Year (Jan–Mar 2026)
To make sure you’re fully “in the know” about upcoming dates and deadlines in the UK accounting and tax calendar, we’ve pulled together some of the most important points, including key filing dates, payments and regulatory changes — all in one place.
📅 Important Deadlines Coming Up
31 January 2026 – Self Assessment
Deadline to submit your online Self Assessment tax return for the 2024–25 tax year. This is also the final day to pay any tax owed to avoid penalties and interest.
Payments on Account (if relevant)
For those who make advance payments towards their next tax bill, the first payment on account for the 2025–26 tax year will also be due by 31 January.
VAT Returns
VAT-registered businesses generally must submit VAT returns and pay VAT within 1 month and 7 days of the end of each VAT accounting period. It’s worth checking your period end dates now to see if deadlines in January, February and March fall due.
PAYE & NIC Payments
Employers must continue to submit Full Payment Submissions (FPS) on or before each payday, and pay PAYE and National Insurance by the 22nd of the month following the pay period.
Corporation Tax
If your company’s accounting period ends during this quarter, corporation tax bills and return deadlines may be due within 9 months after your period end. Plan now to avoid late filing penalties with HMRC.
📌 Regulatory Changes to Watch in Early 2026
The first quarter of 2026 isn’t just about deadlines it marks a couple of major regulatory changes that businesses and advisors should be aware of.
Companies House Fees Change (from 1 February 2026)
From 1 February 2026, Companies House is updating its fee structure for certain filings and services. This means charges for company documents and filings (including annual accounts, confirmation statements and other returns) may be higher or subject to change. It’s worth checking exactly how this affects your business ahead of the change.
Identity Verification for Companies House
To help safeguard company filings and reduce fraud, new identity verification rules are being introduced for certain users filing with Companies House. This means you (or your agents) may need to complete additional identity checks when submitting documents.
Making Tax Digital (MTD) for Income Tax – Starting 6 April 2026
A major tax reporting change — Making Tax Digital (MTD) for Income Tax is due to take effect from 6 April 2026 for self-employed workers and landlords with qualifying income over £50,000. Under MTD for Income Tax, you’ll need to keep digital records and send quarterly summaries to HMRC rather than just a year-end return.
Mark these dates in your diary now to stay organised and avoid costly penalties. If you’re unsure about how a particular deadline affects your business, talk to the Essendon team.