Few situations cause more anxiety than realising your tax affairs are not in order. Whether it is years of undeclared rental income, missed Self Assessment returns, or an error spotted too late, the temptation to do nothing and hope HMRC does not notice is understandable. It is also, in almost every case, the wrong approach. Voluntary disclosure consistently results in better outcomes than waiting to be found out.
Quick Answer: What Is Voluntary Disclosure?
Voluntary disclosure means telling HMRC about tax you owe before they contact you about it. HMRC operates several formal disclosure facilities and also accepts general disclosures at any time. Coming forward voluntarily reduces the penalties you face and demonstrates cooperation, which HMRC takes into account when deciding how to deal with a case. In serious cases, it can also reduce the risk of prosecution.
Why Voluntary Disclosure Leads to Better Outcomes
HMRC imposes penalties on top of the tax owed whenever there has been an error or omission. The size of those penalties depends on several factors, including whether the disclosure was prompted or unprompted.
An unprompted disclosure is one you make before HMRC has any reason to suspect there is a problem. An prompted disclosure is one made after HMRC has already contacted you or made you aware of an investigation.
For the same underlying error, unprompted disclosures attract significantly lower penalties than prompted ones. And both attract lower penalties than cases where HMRC discovers the problem themselves with no cooperation from the taxpayer.
The difference can be substantial. For deliberate errors, penalties can range from 0% (unprompted, with full cooperation) to 100% of the tax owed (no cooperation). Getting ahead of an investigation, even if only a few days, can materially change the penalty level.
HMRC’s Formal Disclosure Facilities
HMRC runs several targeted disclosure campaigns from time to time. These are designed to encourage people in specific situations to come forward. Past campaigns have covered:
- Undeclared rental income (Let Property Campaign)
- Offshore assets and foreign income
- Unpaid Capital Gains Tax
- Tax owed by e-commerce sellers
- Professional contractors using disguised remuneration schemes
If an appropriate campaign is open when you want to disclose, using it is usually the best route because HMRC commits to reduced penalties for participants who use the formal process and disclose fully.
The Let Property Campaign
This is HMRC’s ongoing facility for landlords with undisclosed rental income. It has been running since 2013 and remains open. If you have rental income from UK residential property that has not been declared, this is the correct channel to use.
To use the Let Property Campaign:
- Notify HMRC that you intend to make a disclosure
- Calculate all undisclosed rental income and the tax owed for each year
- Make the disclosure and pay the tax, interest, and any penalties
You can go back as far as 20 years in extreme cases, but most disclosures involve the four or six years HMRC can normally assess depending on whether the omission was careless or deliberate.
How Far Back Does HMRC Look?
HMRC’s ability to investigate historical tax affairs depends on the nature of the error:
- Innocent or careless errors: HMRC can go back four years
- Deliberate errors: HMRC can go back six years
- Fraud or deliberate concealment: HMRC can go back 20 years
When you make a voluntary disclosure, you typically need to cover the same periods. However, the act of coming forward voluntarily and cooperating fully is taken into account and can significantly reduce the time HMRC actually investigates.
What You Need to Include in a Disclosure
A good voluntary disclosure covers:
- All years where there was undeclared income or an error
- The correct tax figure for each year
- Interest (HMRC charges interest from the date tax was originally due)
- A penalty figure, which should reflect the nature of the error and your level of cooperation
Under-disclosing, either accidentally or deliberately, is risky. If HMRC later finds income you did not include in your disclosure, they will treat it as a new discovery and the penalty position worsens significantly.
Getting Professional Help Before You Disclose
This is an area where professional tax advice genuinely earns its fee. Calculating the correct figures, assessing which penalty regime applies, and drafting the disclosure in a way that presents your position in the best light requires careful thought.
A tax specialist can also help you decide which years to include, whether an innocent or careless error argument applies (which affects the penalty rate), and how to structure any payment if you cannot pay the full amount immediately.
HMRC will generally allow a time-to-pay arrangement if the sum owed is significant, but this needs to be negotiated as part of the disclosure process.
Frequently Asked Questions
I have undeclared rental income from several years ago. Will HMRC prosecute me?
Prosecution is rare and reserved for the most serious and deliberate cases. If your undisclosed income arose from genuine carelessness or lack of awareness rather than deliberate fraud, coming forward voluntarily through the Let Property Campaign significantly reduces any risk. Most voluntary disclosure cases are settled through a financial settlement without any criminal proceedings.
I made an error on my tax return that HMRC has not spotted yet. Should I correct it now?
Yes, and the sooner the better. Correcting an error before HMRC raises it gives you the best possible penalty position and demonstrates good faith. You can amend a Self Assessment return within 12 months of the filing deadline, or contact HMRC directly after that.
I owe a lot. What if I cannot pay it all at once?
HMRC can agree a time-to-pay arrangement as part of the disclosure settlement. This is common where the tax owed runs to several thousand pounds. The arrangement will include interest but avoids the need to pay everything in one go. This is something worth discussing as part of the professional advice process.
What if I disclosed but HMRC thinks I have not been fully honest?
This is why getting the disclosure right the first time matters. A disclosure that HMRC believes is incomplete will be treated less favourably and may trigger a formal investigation. Good professional advice before submitting reduces this risk considerably.
Can I disclose on someone else’s behalf, for example a deceased parent’s estate?
Yes. Executors and administrators of estates can make disclosures on behalf of deceased taxpayers. This is more common than people realise and is handled sympathetically by HMRC in most cases.
Talk to a Tax Specialist Before You Approach HMRC
If you are in a position where you know there is undisclosed income or an error in your past returns, the best first step is a confidential conversation with a specialist, not a call to HMRC. Getting the disclosure structured correctly from the outset protects you and leads to significantly better outcomes.
Our principal tax adviser is ACCA qualified, ATT qualified, and an HMRC Registered Tax Agent with over 25 years of experience, including handling HMRC investigations and voluntary disclosures for clients across Kent. We provide confidential, non-judgmental advice and work with you to resolve your tax position as efficiently as possible. Contact us today for a private and confidential conversation.
Also see: HMRC Investigation Support in Gravesend | HMRC Investigation Support in Dartford | HMRC Investigation Support in Maidstone
