Tax Deadlines Every Sole Trader Should Know

Why a Calendar Matters More Than You Think

Running a small business in Haverhill is a juggling act. Between serving customers, chasing invoices and keeping the shelves stocked, the last thing on your mind is a date buried somewhere in HMRC's website. But missed deadlines are one of the most common and most avoidable costs a sole trader faces. A £100 penalty for a late return is money straight out of your pocket, and it's not usually just the once — late payment interest quietly eats into your margins too.

The good news is that the system is predictable. The same dates come round every year, and once you've got them written down somewhere you'll actually look, the whole thing becomes far less stressful. Here's what every sole trader should have marked in the diary.

Registering as a Sole Trader: Your First Deadlines

If you've recently started trading, you need to tell HMRC that you're self-employed. The key date is 5 October following the end of the tax year in which you started. So if you began trading in, say, August 2025, your registration deadline is 5 October 2026. Miss it and you can face a penalty for failing to notify, even if you owe no tax at all.

• Register for Self Assessment as soon as you know you're trading — don't wait for the deadline to creep up.
• You'll receive a Unique Taxpayer Reference (UTR) by post, usually within a couple of weeks. Keep it safe.
• If you're also registering for VAT, that's a separate process with its own timeline.

There's no penalty for registering early, and it gives you a head start on keeping records in order.

The Two Big Filing Dates: 31 October and 31 January

For most sole traders, the tax year runs from 6 April to 5 April. Your Self Assessment tax return for that year is due on:

• 31 October — if you file a paper return.
• 31 January — if you file online, which is what the vast majority of people do now.

The 31 January date isn't just about the return. It's also the deadline for paying any tax you owe for the previous tax year. That's the bit that catches people out: filing and paying land on the same day. Leave it until the last week and you're relying on HMRC's servers behaving perfectly, which is a gamble nobody needs.

Aim to have your figures ready by early January. If you use an accountant — and plenty of Haverhill sole traders do — they'll want your records well before Christmas.

Payments on Account: The Deadline That Catches People Out

If your tax bill is more than £1,000, HMRC usually asks for payments on account. These are advance payments towards your next year's bill, and they fall due on:

• 31 January — the first payment on account.
• 31 July — the second payment on account.

Each is normally half of your previous year's tax bill. This is why January can feel painful: you're settling last year's balance and making a payment towards the current year in one go. The July date is the one people forget, partly because it lands in the middle of summer when business feels quieter.

If your income has dropped and you think the payments on account are too high, you can ask HMRC to reduce them — but do it before the deadline, and only if you're confident about the numbers. Reducing them too far leads to interest charges later.

VAT, Making Tax Digital and Other Dates

Once your turnover passes the £90,000 VAT registration threshold over any rolling 12-month period, you must register for VAT. From that point you'll file VAT returns — usually quarterly — typically one month and seven days after the end of each VAT period. Late submission and late payment both attract penalties under HMRC's points-based system, so it pays to be prompt.

Making Tax Digital for Income Tax is also rolling out, starting with those earning over £50,000 from April 2026, and over £30,000 from April 2027. If you're not there yet, it's worth keeping digital records now rather than scrambling later.

Other dates to keep in mind:

• PAYE payments, if you employ anyone, are due by the 22nd of the following month (or 19th if paying by post).
• Business rates instalments are usually spread over ten monthly payments from April.
• Any licensing or renewal dates specific to your trade — food hygiene, alcohol licences, waste carrier registration — are yours to track, as nobody will chase you.

Building a Simple System That Works

You don't need complicated software to stay on top of this. You need three things: a separate business bank account, a habit of filing receipts weekly rather than annually, and a calendar with reminders set at least a fortnight before every deadline.

Set aside a percentage of every payment you receive into a separate savings pot. A common approach is 25 to 30 per cent for sole traders, adjusted to your own circumstances. By the time January arrives, the money is already there and the deadline becomes a paperwork exercise rather than a financial shock.

If it all feels like a lot, talk to an accountant who knows small firms in and around Haverhill. A few hours of their time each year is often cheaper than a single penalty — and it buys you peace of mind.