Leave It to January: Why Kent Sole Traders and Landlords Should File Self Assessment Early

Every January, the same thing happens. Sole traders and landlords across Kent spend the last week of the month hunting for bank statements, chasing figures and filing their tax return with hours to spare. It is stressful, it is avoidable, and it almost always costs more than doing the same job calmly in the autumn. With the 2025/26 tax year now closed, the sensible move is to get your Self Assessment sorted early — and here is why it pays.

The deadlines that actually matter

Your 2025/26 return covers the tax year that ended on 5 April 2026. The key dates are:

• 31 October 2026 — deadline for a paper return.
• 31 January 2027 — deadline to file online, and to pay any tax you owe for 2025/26.
• 31 January 2027 — also the date your first payment on account for 2026/27 falls due, if you make them.
• 31 July 2027 — your second payment on account for 2026/27.

Almost everyone files online now, so 31 January is the date most Kent business owners have in mind. The trap is treating it as the date to start, rather than the date to finish.

Filing early doesn’t mean paying early

This is the point that changes most people’s minds. Submitting your return in October or November does not mean you have to pay the tax any sooner. Whatever you owe is still due on 31 January 2027. Filing early simply tells you, months in advance, exactly what that bill will be — so you can set the money aside, spread it into savings, or budget around a payment on account without any nasty surprises in the new year.

For anyone with a large or unexpected bill, that early warning is genuinely valuable. If cash is tight, knowing the figure in November gives you time to arrange a Time to Pay plan with HMRC, which you can usually set up online where you owe less than £30,000. Leave it to the last week of January and your options narrow fast.

What being late really costs now

The price of missing the deadline has climbed, and it is worth being blunt about the numbers. Miss the filing deadline and you get an automatic £100 penalty — even if you owe no tax at all, and even if you were only a day late. Further penalties stack up the longer a return is outstanding.

Pay late and it costs more still. HMRC charges late-payment interest at 7.75% a year (the Bank of England base rate of 3.75% plus 4%), running daily from 1 February until you clear the balance. On top of that sit surcharges: broadly a further 5% of the tax still unpaid after 30 days, again at six months and again at twelve months. For a Kent landlord or trader with a few thousand pounds of tax to find, those charges add up to real money — all of it entirely avoidable.

Get your records in order while it’s quiet

The autumn is simply a better time to do the work. Your records are fresher, your accountant has more room to look properly at your figures, and there is time to ask questions rather than firefight. Before you (or we) start, it helps to gather:

• Business income and expenses for the year to 5 April 2026, with receipts and bank statements to back them up.
• Rental income and allowable costs, if you are a landlord — including mortgage interest, so the finance-cost tax credit is claimed correctly.
• Details of any other income: employment (with your P60), pensions, savings interest, dividends or capital gains.
• Records of pension contributions and Gift Aid donations, which can reduce your bill.

Remember too that the first £1,000 of casual trading income and the first £1,000 of property income are each covered by a tax-free allowance. If your side income sits below that, you may not need to report it at all — and a quick check now saves needless worry later.

A change on the horizon worth knowing about

Two shifts are coming that make good record-keeping matter even more. First, the point at which you must file a full return for casual trading income is set to rise from £1,000 to £3,000 of gross income, expected from the 2027/28 tax year, with a simpler online service for smaller amounts. The tax-free trading allowance stays at £1,000, so tax can still be due between the two figures — it is the paperwork that eases, not the tax.

Second, and more significant, Making Tax Digital for Income Tax reaches sole traders and landlords with qualifying income over £30,000 from April 2027. That means digital records and quarterly updates to HMRC. Getting into the habit of clean, up-to-date bookkeeping now is the best possible preparation — and one more reason not to leave everything to a January scramble.

How MCC Partners can help

We prepare and file Self Assessment returns for sole traders, landlords and company directors right across Gravesend, Dartford, Medway and the rest of Kent. File with us in the autumn and you will know your bill months ahead, have time to plan for it, and start the new year without the usual dread. We will also make sure every allowance and expense you are entitled to is claimed — which often more than covers our fee.