Frequently Asked Questions
Is my data private?
Yes. All calculations happen entirely in your browser. No data is sent to any server. Your inputs are only saved to your device's local storage if you click Save.
Is this professional tax advice?
No. This calculator provides estimates only based on published HMRC rates. It does not constitute professional tax, financial, or legal advice. Always consult HMRC or a qualified tax adviser for your specific situation.
How accurate are the results?
The calculator uses official HMRC tax bands, personal allowance figures, and flat-rate expense amounts for the selected tax year. However, individual circumstances vary — your actual refund may differ due to factors not captured by the calculator.
When was the data last updated?
The calculator uses 2025/26 HMRC rates (effective from 6 April 2025). We update all rates and thresholds at the start of each new tax year.
Can I export my results?
Yes. After calculating your rebate, click the 'Export as PDF' button to download a print-friendly summary of your results including all inputs, the tax band breakdown, and a timestamp.
How do I report an error?
Please use our contact form to report any calculation errors, broken features, or incorrect data. We take accuracy seriously and investigate all reports promptly.
Which tax years are supported?
The calculator supports the current tax year (2025/26) plus the four previous years: 2024/25, 2023/24, 2022/23, and 2021/22. This matches the HMRC backdating window for rebate claims.
Does it work for Scottish taxpayers?
Yes. Select 'Scotland' in the tax region toggle and the calculator uses Scottish income tax bands automatically. The personal allowance and National Insurance rates are the same across the UK.
What is Marriage Allowance?
Marriage Allowance lets you transfer £1,260 of your personal allowance to your spouse or civil partner if you earn under £12,570 and they are a basic-rate taxpayer. This can save up to £252 per year.
Do I need to pay a company to claim my rebate?
No. You can claim directly from HMRC for free through your Personal Tax Account, by calling them, or by posting form P87. Tax rebate companies typically charge 30-50% of your refund as a fee for doing something you can easily do yourself.
Can I claim for previous years?
Yes. You can backdate claims for the current tax year plus the previous four years. Our calculator supports all five years so you can check each one.