HMRC penalties escalate over time. A £100 fine becomes £900+after 6 months. Don't wait.

Based on HMRC's own reasonable excuse guidelines

Appeal your tax penalty in 2 minutes.

Enter your HMRC penalty details and get a formal appeal letter citing the exact legislation and case law that wins appeals. Built on the Perrin v HMRC reasonable-excuse test.

Free assessment. No sign-up. 256-bit SSL encrypted. Based on HMRC's own reasonable excuse guidelines. Cites Perrin v HMRC case law.

1.1M
Penalties issued yearly
30 days
Appeal deadline
2 min
To generate
£19.99
One-time fee
Built on Finance Act 2009 + Perrin v HMRC
Based on HMRC's own reasonable excuse guidelines
Penalties increase after 30 days — don't wait
Legal foundations

Every appeal grounded in UK tax law

TaxFlip cites the exact legislation for your penalty type — Self Assessment, VAT, Corporation Tax, or PAYE.

Taxes Management Act 1970

Core Self Assessment penalty provisions including s.93 (late filing) and s.86 (late payment interest).

Finance Act 2009

Schedule 55 (late filing penalties) and Schedule 56 (late payment penalties) — the modern penalty regime.

Perrin v HMRC Precedent

The structured legal test for reasonable excuse established in [2018] UKUT 156 — cited in every strong appeal.

SA370 Form Knowledge

Generates text optimised for the official HMRC appeal form or a standalone formal appeal letter.

30-Day Deadline Tracking

Alerts you to your appeal deadline and provides urgency guidance based on when your penalty was issued.

Tribunal Escalation Guidance

If HMRC rejects your appeal, guidance on requesting a statutory review or appealing to the First-tier Tribunal.

How it works

Three steps to a professional appeal

No tax knowledge needed. TaxFlip does the heavy lifting.

Step 1

Enter your penalty details

Penalty type, tax year, reference number, and your reasonable excuse. Takes 60 seconds. All HMRC penalty types supported.

Step 2

AI drafts your appeal letter

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.

Step 3

Send to HMRC

Copy your appeal to submit online via Government Gateway, or download to post with form SA370. We tell you exactly where to send it.

Common questions

Frequently asked 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

One price. No subscription.

£19.99/appeal

Your penalty is at least £100. This costs less than a stamp.
Free assessment of your chances before you pay.

256-bit SSL encryptedSA370-friendly wordingFree assessment included

HMRC penalties escalate: £100 becomes £900+ after 6 months. Your 30-day appeal window is ticking.

  • Full formal appeal letter
  • Correct UK tax legislation cited
  • Perrin v HMRC legal test addressed
  • Sending instructions & deadlines
  • Copy, print, or download
  • Tribunal escalation guidance
Appeal My Tax Penalty - £19.99

Cheaper than the penalty. Smarter than ignoring it.

Don't just pay it. Appeal 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 £19.99.

Free assessment. No sign-up. Takes 2 minutes.