Why Now Is the Best Time to Start Your Self Assessment

Every January, the same thing happens: HMRC's phone lines jam, inboxes fill up, and accountants across the country field a wave of "can we still get this done in time?" messages. The irony is that the tax year in question ended nine months earlier. There is no rule that says Self Assessment has to be a January scramble — it's simply become a habit for a lot of people. Mid-September is a much better time to break that habit. 

 

 

For the 2025–26 tax year, the key dates are still what they've always been: 31 October for paper returns, and 31 January for online returns and any balancing payment owed. If you also make payments on account, the second one for the year falls on 31 July. None of that changes — what changes is how much stress you go through to hit those dates. 

 

 

Starting now doesn't mean finishing your return today. It means doing the small things that make the eventual filing quick and painless: 

 

Gather your records while they're fresh. Bank statements, invoices, expense receipts, and any income from property, dividends, or savings are all far easier to pull together in September than to reconstruct in January, especially if a record has gone missing and needs replacing. 

 

Get an early estimate of what you'll owe. Once we can see roughly where your figures land, you can start setting money aside rather than facing a tax bill in January that you haven't planned for. This is especially useful if your income has changed significantly from the previous year. 

 

Give yourself room to ask questions. If something in your return is unusual — a new source of income, a change in circumstances, a relief or allowance you're not sure you qualify for — there's time in September to look into it properly. In January, there often isn't. 

 

Avoid the last-minute software and access issues. Every year, some of the January rush is simply people who can't remember their Government Gateway login, or whose software needs an update they didn't plan for. Sorting this in advance removes one more thing that can go wrong at the worst possible time. 

 

 

The value of filing early isn't really about beating a deadline — the deadline is the same either way. It's about turning your tax return from a once-a-year fire drill into a routine task you have full visibility over. You find out what you owe (or what you're due back) with months to plan around it, rather than weeks or days. 

 

If you're due a refund, filing early also means you're not waiting until February to see that money — HMRC generally processes early returns just as quickly as late ones, so there's no advantage to holding off. 

 

 

If you'd like to get your 2025–26 Self Assessment out of the way well before the rush, now is the ideal time to send over your records. Get in touch with us at Bidwell Accountancy and we'll help you turn this January into a quiet one.