What happens if I don't respond to a letter from HMRC?
Silence is viewed as Guilt
HMRC is one of the few organisations that can legally assume you owe money unless you prove otherwise. If they write to you asking for information and you ignore them, they will not just go away.
The Risks of Silence:
- Determination: HMRC will GUESS your tax bill. They usually guess high to force a reaction. You cannot appeal this guess; you have to file a proper return to displace it.
- Daily Penalties: If you ignore a formal "Information Notice" (Schedule 36), they appeal to a tribunal to charge you £60/day until you comply.
- Criminal Investigation: Persistent silence can be viewed as "Concealment", moving a civil check into a criminal investigation.
Use the tools below to understand what letter you have received and how to respond safely.
1 The Typical Timeline
If you take no action, this is the standard statutory process. Timescales are approximate but typical for 2026.
The Nudge / Check
HMRC asks for clarification. They might have data (e.g. bank interest) that doesn't match your return.
Schedule 36 Notice
A formal legal order to provide documents. Ignore this and you get a fixed £300 fine.
Daily Penalties
If you still ignore them, they apply to the Tax Tribunal for daily penalties (up to £60/day).
determination
HMRC issues a 'Determination'. They estimate your tax (e.g. £50k) and demand payment. This is legally enforceable.
2 Free Calculators & Checks
Got a code on your letter like 'CFSS' or 'Sch36'? Find out exactly what it means.
Decode Your Letter
Select the type of letter or code you received.
See how fast the daily fines add up if you stick your head in the sand.
The Cost of Silence
See how fast daily penalties add up if you ignore an Information Notice.
Late with a good reason? Draft a professional appeal letter in seconds.
Appeal Letter Writer
Generate a penalty appeal based on 'Reasonable Excuse'.
HM Revenue & Customs [Address from your Penalty Notice] Date: 1/16/2026 Dear Sir/Madam, **Appeal Against Penalty Notice: [Insert Penalty Reference]** **Taxpayer Reference (UTR): [Insert UTR]** I am writing to formally appeal against the penalty issued on [Date] regarding the late filing/payment of my tax return. I believe I have a 'Reasonable Excuse' for this failure as defined in your guidance. **The Reasonable Excuse:** **Details:** [Add 1-2 sentences with specific dates/details here] This situation was unforeseeable and outside of my control. I have now remedied the failure by [filing the return/paying the tax] as soon as the excuse ceased. I therefore request that this penalty be cancelled. Yours faithfully, [Your Name]
Timeline Danger Check
What is a 'Determination'?
A Revenue Determination is HMRC's "Nuclear Option".
If you don't file a return or provide info, they have the legal power to estimate what tax you owe.
- The Trap: They often estimate much higher than your actual liability based on your past income or industry averages.
- The Fix: You CANNOT Appeal a determination. The only way to get rid of it is to submit the missing tax return within 12 months.
- The Danger: If you miss that 12 month window, the estimated bill becomes legally fixed. You owe that money forever, even if you earned £0.
Reasonable Excuses
If you are late responding, you can avoid penalties if you have a "Reasonable Excuse".
Accepted Excuses:
- Close family bereavement.
- Unexpected hospital stay.
- Serious illness (not just a cold).
- Computer/Software failure at the time of the deadline.
- Fire, flood, or theft of records.
Rejected Excuses:
- "I relied on my accountant." (You are responsible).
- "I didn't have the money."
- "I found the form too difficult."
Summary of Options
Call Them
If you need more time, call. HMRC is surprisingly helpful if you communicate. They only get aggressive when ignored.
Check Validity
Is the request 'Reasonable'? You can appeal a Schedule 36 notice if they are asking for irrelevant old documents.
Ignore It
Result: A huge estimated tax bill (Determination) that is legally owed and enforced by debt collectors.
Common Questions
Can they really charge £60 a day?
Yes. Under Schedule 36 Finance Act 2008, if you ignore an information notice, the Tribunal can authorise daily penalties until you comply.
What if I lost the letter?
Call HMRC immediately. They can re-send it or tell you what they need. 'I didn't get the letter' is rarely accepted as an excuse unless you can prove postal issues.
Do I need an accountant?
For a simple check, maybe not. For a 'Schedule 36' notice or a widespread investigation, YES. You need professional representation to stop HMRC overreaching.
Official Sources & References
Related Situations
Other guides accurately explaining what happens next in tax & hmrc .
What happens if HMRC freezes my bank account?
HMRC has two ways to stop your cash: Civil debt collection (DRD) or Criminal investigation (AFO). Know which one you are facing and how to protect your living costs.
What happens if I'm reported to HMRC?
Being reported for tax evasion is stressful. HMRC's 'Connect' system will analyse your data. If you have undeclared income, telling them BEFORE they investigate reduces penalties significantly.
What happens if I don't file a Tax Return?
HMRC penalties are severe and automatic. A simple £100 fine can escalate to over £1,600 within 6 months due to daily penalties. Ignoring HMRC is the most expensive mistake you can make.