Enter your HMRC penalty details. Our AI generates a formal appeal letter citing the correct UK tax legislation — the same arguments a chartered tax adviser would use.
Free assessment. No sign-up. Pay only if you want the full letter.
TaxFlip cites the exact legislation for your penalty type — Self Assessment, VAT, Corporation Tax, or PAYE.
Core Self Assessment penalty provisions including s.93 (late filing) and s.86 (late payment interest).
Schedule 55 (late filing penalties) and Schedule 56 (late payment penalties) — the modern penalty regime.
The structured legal test for reasonable excuse established in [2018] UKUT 156 — cited in every strong appeal.
Generates text optimised for the official HMRC appeal form or a standalone formal appeal letter.
Alerts you to your appeal deadline and provides urgency guidance based on when your penalty was issued.
If HMRC rejects your appeal, guidance on requesting a statutory review or appealing to the First-tier Tribunal.
No tax knowledge needed. TaxFlip does the heavy lifting.
Penalty type, tax year, reference number, and your reasonable excuse. Takes 60 seconds. All HMRC penalty types supported.
A formal letter citing the Taxes Management Act 1970, Finance Act 2009, and relevant case law — structured to meet the Perrin v HMRC legal test.
Copy your appeal to submit online via Government Gateway, or download to post with form SA370. We tell you exactly where to send it.
“Got the £100 late filing penalty even though I was in hospital. TaxFlip drafted an appeal citing my medical situation as a reasonable excuse. Penalty cancelled within 3 weeks.”
Michael K.
Leeds
“HMRC's website crashed on 31st January and I filed 2 hours late. The appeal letter cited the IT failure reasonable excuse with exact timestamps. Penalty removed.”
Sarah P.
London
“My accountant let me down and I got hit with £1,300 in penalties. TaxFlip wrote a detailed appeal covering multiple penalty periods. All but £100 was cancelled.”
James W.
Birmingham
Common questions
Yes. If you have a reasonable excuse — such as serious illness, bereavement, fire, flood, IT failure, or HMRC's own error — you can appeal within 30 days of the penalty notice. Over 1 million penalties are issued each year, and many are successfully appealed.
HMRC accepts: serious illness or disability, bereavement, fire or flood, computer/software failure, postal delays, HMRC errors, and mental health conditions. They do NOT accept: 'I forgot', 'I was too busy', 'I didn't know about the deadline', or 'I couldn't afford to pay'.
TaxFlip identifies your penalty type (late filing, late payment, VAT, Corporation Tax, PAYE) and applies the correct legislation — Taxes Management Act 1970, Finance Act 2009 Schedule 55/56, or VAT Act 1994. It also cites the Perrin v HMRC legal test for reasonable excuse.
No. TaxFlip generates appeal letters based on publicly available UK tax legislation and established case law. It does not constitute formal legal advice. For complex cases or tribunal appeals, we recommend consulting a chartered tax adviser or solicitor.
HMRC aims to respond within 45 days. If they accept your appeal, the penalty is cancelled. If they reject it, you can request a statutory review by a different HMRC officer, or appeal directly to the First-tier Tribunal (Tax Chamber) — which is free and independent of HMRC.
You can try. If you have a good reason for the late appeal — such as not receiving the penalty notice, or ongoing illness — HMRC may still consider it. TaxFlip will include a paragraph explaining the late appeal if applicable.
Pricing
Your penalty is at least £100. This costs less than a stamp.
Free assessment of your chances before you pay.
Cheaper than the penalty. Smarter than ignoring it.
Most people pay HMRC penalties they could have successfully appealed. TaxFlip gives you the same legal arguments a chartered tax adviser would use — for £4.99.
Free assessment. No sign-up. Takes 2 minutes.