The UK tax season runs differently from the calendar year. It starts on 6 April and ends on 5 April the following year, and if you are self-employed, a company director, or receive untaxed income, you must file a Self Assessment return. For women running businesses, the cost of getting it wrong is real: missed deadlines, underclaimed expenses, or ignored thresholds can mean money leaves your company that you could have kept. Below are eight practical things to remember for the 2026/27 UK tax season, based on current HMRC guidance and the rates the government has frozen or announced to date.
1. Map out the UK tax season calendar
The 2026/27 tax year runs from 6 April 2026 to 5 April 2027. If you submit a paper Self Assessment return, the deadline is 31 October 2027. If you file online, the deadline is 31 January 2028. Under current HMRC rules, an online return that is up to three months late attracts an automatic £100 penalty, with further daily and percentage penalties after that. Interest also applies to late payments from the original due date, so diarise both dates now.
2. Check your income tax bracket and National Insurance
The personal allowance remains at £12,570, frozen at that level until 2027/28 under the March 2024 Budget. Income between £12,571 and £50,270 is taxed at the basic rate of 20%, the higher rate of 40% applies between £50,271 and £125,140, and the additional rate of 45% applies above £125,140. If you are self-employed, Class 4 National Insurance contributions are currently 6% on profits between £12,570 and £50,270 and 2% on profits above that, based on the 2024/25 and 2025/26 rates. Voluntary Class 2 contributions are £3.50 a week in 2024/25 and 2025/26 if your profits are below £12,570 and you want to protect your State Pension record. Knowing these bands helps you set aside the right amount each month.
3. Register for Making Tax Digital if you qualify
HMRC’s current timetable makes Making Tax Digital for Income Tax Self Assessment mandatory from April 2026 for unincorporated businesses and landlords with gross income above £50,000, and from April 2027 for those with income above £30,000. You must keep digital records and send quarterly updates using MTD-compatible software. If your turnover is below the threshold, you can still volunteer. Our Making Tax Digital sole trader checklist sets out what women in business need before the first quarterly deadline.
4. Claim every allowable expense
Allowable expenses reduce your taxable profit. For the self-employed, this includes office costs, travel, staff wages, stock, marketing, and a proportion of home-working costs. HMRC allows a simplified flat rate of £10 to £26 a month for working from home, depending on hours worked there, or you can claim a proportion of actual bills. See our guide to allowable expenses for the self-employed. If you trade through a limited company, review your salary and dividend mix carefully: the dividend allowance is £500 from 2024/25 onwards, and dividend tax is charged at 8.75% for basic rate, 33.75% for higher rate, and 39.35% for additional rate taxpayers.
5. Watch the child benefit high income charge
If you or your partner claim child benefit and either of you earns between £60,000 and £80,000, the high income child benefit charge claws back 1% of the payment for every £100 of income over £60,000. Above £80,000, the charge equals the full benefit. These thresholds took effect from April 2024. Because the charge is based on the highest earner’s adjusted net income, pension contributions, Gift Aid, and allowable business expenses can bring you back under the threshold.
6. Keep records for the right length of time
HMRC can ask to see your business records up to five years after the 31 January online filing deadline for a tax year. That means records for 2026/27 must be kept until at least 31 January 2033. Store sales invoices, purchase receipts, bank statements, mileage logs, and dividend vouchers digitally if you use MTD-compatible software, or in a secure physical file. Good record keeping is also your strongest defence if HMRC opens an enquiry.
7. Decide how you will file
You have three main routes. You can file through HMRC’s free online Self Assessment service if your tax affairs are straightforward. You can use commercial tax software, which is increasingly necessary for MTD quarterly reporting. Or you can hire an accountant or tax adviser, whose fee is itself an allowable business expense. The right choice depends on your turnover, business structure, and how confident you are with tax law. Many women founders find that professional support pays for itself in saved tax and avoided penalties.
8. Budget for payments on account
If your Self Assessment tax bill is more than £1,000 and less than 80% of your tax is collected at source, HMRC will ask for payments on account. These are advance payments towards next year’s bill, due by 31 January and 31 July. The first payment on account for 2026/27 is due by 31 January 2028, alongside any balancing payment for 2025/26. Set aside roughly 20% to 30% of your profit each month so you are not caught short.
Action steps for the 2026/27 tax season
- Mark 31 January 2028 and 31 July 2028 in your diary.
- Check whether your income puts you above the £50,000 MTD threshold from April 2026.
- Review your last three months of expenses and file any missing receipts.
- Estimate your 2026/27 tax and NICs liability and open a separate savings account for it.
- If your household claims child benefit, calculate whether the high income charge applies.
The UK tax season does not have to be a scramble. A small amount of planning now, using the current HMRC thresholds and deadlines, keeps more money in your business and reduces the risk of penalties. For a fuller breakdown of rates and reliefs, read our complete guide to self-employed tax in 2026/27.
