Over 11.5 million people met the 31 January 2025 self-assessment deadline, but 1.1 million taxpayers missed it. If you're one of them, expect a £100 penalty. Learn about late fees and HMRC’s payment plan options to avoid further charges.

There are an estimated 1.1 million taxpayers that missed the deadline. Are you among those that missed the 31 January 2025 filing deadline for your 2023-24 self-assessment returns?

If you have missed the filing deadline then you will usually be charged a £100 fixed penalty if your return is up to 3 months late, regardless of whether you owed tax or not. If you do not file and pay before 1 May 2025 then you will face further penalties unless you have arranged to pay with HMRC.

If you are unable to pay your tax bill, there is an option to set up an online time to pay payment plan to spread the cost of tax due on 31 January 2025 for up to 12 months. This option is available for debts up to £30,000 and the payment plan needs to be set up no later than 60 days after the due date of a debt.

If you owe self-assessment tax payments of over £30,000 or need longer than 12 months to pay in full, you can still apply to set up a time to pay arrangement with HMRC, but this cannot be done using the online service.

Big changes are here for the self-employed! From 2024-25, profits must align with the tax year, replacing the old "current year basis." Overlap relief is ending, and transition profits will be spread over five years. Here’s how the new system affects your tax bill.

The reform to the self-employed tax basis period has introduced significant changes in how trading income is allocated to tax years. Previously, the tax basis period operated on a "current year basis," but the reform has now shifted to a "tax year basis." As a result, all sole traders and partnership businesses are required to report their profits based on the tax year, commencing with the self-assessment return that was due by 31 January 2025. This return covered the tax year 2023-24.

Under the previous system, overlapping basis periods could occur, which resulted in certain profits being taxed twice. To counter this, businesses could claim ‘overlap relief,’ typically at the time of business cessation. The introduction of the "tax year basis" eliminates the possibility of overlapping basis periods, thereby preventing the generation of further overlap relief.

It is important to note that businesses which already prepare annual accounts to a date between 31 March and 5 April are not affected by these changes. These businesses continue to file their tax returns as they did under the old system, without any alteration.

The full implementation of the new rules takes effect in the current 2024-25 tax year, which ends on 5 April 2025. The 2023-24 tax year is considered a "transition year." During this transitional period, the basis periods for all businesses will be aligned with the tax year, and any outstanding overlap relief can be utilised against profits for that period.

In cases where profits exceed the period covered by the overlap relief—specifically profits that span more than 12 months—these are referred to as "transition profit." This transition profit will, by default, be spread across five tax years, from 2023-24 to 2027-28, to help ensure a smooth adjustment to the new rules.

Your tax code determines how much tax is deducted from your pay. While 1257L is the most common, different letters and numbers can affect how much you owe. From marriage allowance to emergency codes, here’s how to decode what HMRC assigns you.

Your tax code is basically a set of letters and numbers that show whether you are entitled to the annual tax-free personal allowance (the amount you can earn without paying tax). These codes are updated each year and help your employer figure out how much tax to take off your pay.

For the current and next tax years, the standard personal allowance is £12,570, and if you are entitled to this, your tax code will likely be 1257L. This is the most common code and applies to people with one job, no untaxed income, and no taxable benefits like a company car.

But tax codes are not always that straightforward. There are all sorts of other letters and numbers that might pop up. For example, if you are claiming the marriage allowance, your code might have an "M" in it. If you are paying tax at the Scottish rates, your code will start with an "S." And if your personal allowance gets reduced for some reason, like unpaid tax or income adjustments, your code will change accordingly.

Then there are the emergency tax codes—W1 or M1—which are used when someone starts a new job and does not have a P45 yet. These codes mean your tax will be calculated based on just that specific pay period, rather than your full income.

If you spot a 'K' at the start of your tax code, it means deductions (for things like company benefits, state pension, or previous tax owed) are greater than your personal allowance. Your tax deduction won’t be more than half of your pay or pension.

From 6 April 2025, the remittance basis of taxation will be scrapped in favour of a residence-based system. A new 4-year Foreign Income and Gains regime offers tax relief for new arrivals, while transitional measures aim to ease the shift. Here’s what’s changing.

Effective from 6 April 2025, the remittance basis of taxation for non-UK domiciled individuals will be replaced by a simplified, residence-based tax regime.

Additionally, the government will introduce a 4-year Foreign Income and Gains (FIG) regime. Under this regime, individuals newly arriving in the UK who choose to participate will receive full relief (100%) on foreign income and gains during their first four years of UK tax residence, provided they have not been UK tax resident in any of the preceding 10 consecutive years.

As a transitional measure for Capital Gains Tax (CGT) purposes, individuals who have previously used the remittance basis will have the option to rebase personally held foreign assets to their value as of 5 April 2017, provided certain conditions are met.

Furthermore, Overseas Workday Relief will be extended to cover a 4-year period, in line with the new 4-year FIG regime. This change will eliminate the need for individuals using this relief to keep their employment income offshore. From 6 April 2025, the maximum amount of Overseas Workday Relief that can be claimed annually will be the lesser of £300,000 or 30% of the individual's net employment income.

A new Temporary Repatriation Facility (TRF) will also be introduced from April 2025 for a 3-year period. This facility will allow individuals who have previously been taxed on the remittance basis to designate and remit foreign income and gains that arose prior to the reform, at a reduced rate. This includes foreign income and gains held within trust structures that have not been attributed. The TRF will offer a rate of 12% for the first 2 years, and 15% in the final year of its operation.

Gift Aid transforms charitable donations by allowing charities and CASCs to claim 25p extra for every £1 given—at no additional cost to you. Higher and additional rate taxpayers can also claim valuable tax relief, making giving even more rewarding.

Higher and additional rate taxpayers can claim tax relief on the difference between the basic rate of tax and their highest rate. This can be done through their self-assessment tax return or by requesting HMRC to adjust their tax code.

Example: 

If a taxpayer donates £1,000 to charity, the total value of the donation to the charity is £1,250. The taxpayer can claim additional tax relief based on their tax rate:

• £250 if they pay tax at 40% (£1,250 × 20%)
• £312.50 if they pay tax at 45% (£1,250 × 25%)

It is important to ensure that the taxpayer has paid enough tax in the relevant year. Donations will qualify for tax relief as long as the total claimed does not exceed four times the amount of tax paid in that year. If more tax relief is claimed than entitled, the taxpayer must notify the charity and repay the excess to HMRC.

Additionally, taxpayers can make donations directly from their wages through a payroll giving scheme if their employer operates one approved by HMRC. This allows donations to be made tax-free from salary or pension payments.