UK self-assessment deadline 31 January — how to complete your 2024–25 return

The deadline to file a UK self-assessment tax return for the tax year from 6 April 2024 to 5 April 2025 is 31 January, and HM Revenue and Customs is urging people to start now rather than leave it until the last minute to avoid mistakes and busy phone lines. If you are unsure whether you need to file, HMRC provides an online tool to check.

Gather documents such as P60s, P45s, P11Ds, PAYE coding notices and investment tax certificates before you begin; this may involve logging into employer systems or asking others. HMRC’s free app can supply key details — including your self-assessment unique taxpayer reference and employment income — let you set payment reminders and offer digital assistance.

Watch for common issues that trigger returns: if you earned more than £1,000 from informal trading or side hustles in 2024–25 you must register for self-assessment; the trading allowance is £1,000. Savings interest may now exceed personal savings allowances (£1,000 for basic-rate and £500 for higher-rate taxpayers); at 4% interest the thresholds cited are about £25,000 for basic-rate and £12,500 for higher-rate payers.

Pension tax relief rules vary by scheme (net pay vs relief at source) and higher-rate taxpayers using relief-at-source usually need to claim extra relief on the return (for example, entering £875 on the form for a £700 contribution as explained). The high-income child benefit charge kicks in at £60,000 of adjusted net income, and HMRC offers a calculator for estimates.

Key Topics

Business, Self Assessment, Hmrc, Trading Allowance, Savings Allowance, Pension Tax Relief