What this letter usually means

A nudge letter is what HMRC call a one to many letter. Rather than targeting one person after an enquiry, HMRC send the same letter to many taxpayers at once because data they hold suggests those people may have income or gains that have not been fully declared. The letter nudges you to check your own position and put things right if needed.

Common topics include overseas income or assets, property and rental income, cryptoasset gains, dividends, and income from online platforms and other side income. HMRC receive data from banks, other countries, platforms and registries, and they use it to spot people whose returns may not match. The letter usually asks you to either confirm that everything is correct or to correct your position, sometimes through a disclosure facility.

Importantly, a nudge letter is not a formal enquiry and not an accusation. It is a prompt. But it is a prompt backed by real data, and it should be taken seriously and answered.

Who it affects

Nudge letters go to a wide range of people, often those with income outside their main job or business. You might receive one if you have a rental property, money or assets abroad, gains from selling cryptoassets, dividend income, or earnings from online selling, content platforms or the gig economy. Many recipients are otherwise fully compliant and simply missed something, or did not realise it was taxable.

If you have side income alongside employment, it is worth understanding how it should be reported. Our Self Assessment guide explains who needs to file and how extra income is declared. People are often caught out because they assumed small or occasional income did not count, or that tax abroad was the end of the matter.

Receiving a nudge letter does not mean you are in trouble. It means HMRC hold data that prompted them to ask you to check. The right response is to check honestly and act on what you find.

What you must not ignore

Although a nudge letter is not a formal enquiry, it must not be ignored. HMRC have sent it because their data flagged you, and choosing to do nothing does not make that data go away. If there is undeclared income or gains and you fail to act, HMRC can later open a formal investigation, and at that point the outcome is usually worse.

The reason early action matters is the way penalties work. If extra tax is due, penalties depend on whether the error was careless or deliberate, and crucially on whether any disclosure was prompted or unprompted, and made before or after HMRC took further action. Acting on a nudge letter early, and making a voluntary disclosure if needed, almost always means lower penalties than waiting to be investigated.

So the letter should not cause panic, but it should not be put aside either. Whether your position is already correct or needs putting right, the safe response is to check it properly and respond.

What you may need to gather

To check your position accurately, gather the records that relate to whatever the letter mentions. Depending on your circumstances that might include:

  • Rental income and expenses, with statements and receipts, for each property
  • Records of overseas income, assets, and any foreign tax already paid
  • Cryptoasset transaction histories showing buys, sells and gains
  • Dividend vouchers and investment statements
  • Statements from online platforms showing your earnings
  • Copies of the tax returns for the years in question

If you are reviewing rental income, our guide to allowable expenses helps you work out the correct taxable profit rather than just the rent received, so you neither under nor over declare. Good bookkeeping makes this review far easier and gives you confidence in the figures you report.

What to do, step by step

A nudge letter is most manageable when you take it in clear steps.

  • Read the letter carefully. Note exactly what it is asking about, whether overseas income, property, crypto, dividends or online income.
  • Do not ignore it, and do not panic. It is a prompt to check, not a verdict.
  • Review your position honestly. Check whether the income or gains were fully declared for the years involved.
  • If everything is correct, respond to confirm your position as the letter asks.
  • If something was missed, consider a voluntary disclosure to put it right, often through a disclosure facility.
  • Get advice before responding if you are unsure, especially before making a disclosure, so it is done correctly.
  • Keep copies of the letter, your workings and anything you submit.

Done properly, a disclosure brings your affairs up to date on your own terms and usually at lower cost than waiting.

A worked example

Example

Untaxed rental income and a voluntary disclosure

Sara rents out a flat she inherited a few years ago. She declared nothing, partly because she assumed the small surplus after the mortgage was not taxable. One morning she receives an HMRC nudge letter mentioning property and rental income and asking her to check her position. She feels sick with worry.

Sara speaks to an accountant rather than ignoring the letter. Together they work out the actual taxable profit for each year, deducting the allowable expenses she was entitled to claim, such as letting costs and certain repairs, rather than just looking at the rent. The amounts owed turn out to be smaller than she feared, because her real profit was modest once expenses were taken into account.

Because there was undeclared income, the accountant helps Sara make a voluntary disclosure through the appropriate facility, reporting the correct figures and paying the tax and interest due. As the disclosure was made promptly and voluntarily after the nudge, rather than after a formal investigation, the penalties are kept low. Sara is now fully up to date and can carry on letting the flat with peace of mind. Acting on the letter early turned a frightening situation into a tidy resolution.

When to speak to an accountant

It is well worth speaking to an accountant when a nudge letter arrives, especially if you think something may have been missed or you are unsure how to respond. Disclosures need to be accurate and made through the right route, and the way you handle the first response can affect both the tax and the penalty.

An accountant can review your position calmly, work out the correct figures including any expenses or foreign tax relief, advise whether a disclosure is needed, and handle it properly on your behalf. If matters ever move beyond a nudge, our compliance check guide explains what a formal enquiry involves and how representation helps. Acting early with good advice is what keeps things low cost and low stress.

If you have received a nudge letter, you do not need to face the figures alone. You can book a call with us, or start your quote with a fixed fee quote so you know exactly where you stand before deciding what to do.

In short

A calm guide to HMRC nudge letters, why they are sent, that they are not a formal enquiry, and how a voluntary disclosure usually means lower penalties.

Frequently asked questions

Is a nudge letter a tax investigation?
No. A nudge letter is a one to many letter sent to many taxpayers at once based on data HMRC hold. It is not a formal enquiry or investigation. It is a prompt asking you to check your position and either confirm everything is correct or put it right. It should be taken seriously and answered, but it is not an accusation.
Why did I receive an HMRC nudge letter?
HMRC send nudge letters when data they hold suggests you may have income or gains that have not been fully declared. The data comes from banks, other countries, online platforms and registries. Common triggers include overseas income, rental property, cryptoasset gains, dividends and income from online platforms. Receiving one does not mean you are in trouble, only that something prompted HMRC to ask you to check.
What happens if I ignore a nudge letter?
Ignoring it does not make HMRC's data disappear. If there is undeclared income or gains and you do nothing, HMRC can later open a formal investigation, and the outcome at that stage is usually worse, including higher penalties. Acting early, and disclosing if needed, almost always leads to a better result than waiting to be investigated.
Will making a disclosure mean lower penalties?
Usually, yes. If extra tax is due, penalties depend on whether the error was careless or deliberate and whether the disclosure was prompted or unprompted. A voluntary disclosure made promptly after a nudge, rather than after a formal investigation, generally attracts lower penalties. Making things right early, through the proper disclosure facility, is the way to keep penalties down.
The letter is about rental income. How is the tax worked out?
Tax is charged on your taxable rental profit, not simply the rent received. You deduct the expenses you are allowed to claim, such as certain letting costs and repairs, to reach the profit. This often means the amount owed is smaller than people fear. Working out the correct figure carefully helps you neither under nor over declare.
Should I respond to the nudge letter myself or get help?
If your affairs are clearly in order, you can respond to confirm your position. If you think something was missed, or you are unsure, it is wise to get advice before responding, especially before making a disclosure. A disclosure must be accurate and made through the right route, and how you handle the first response can affect both the tax and the penalty.