What is HMRC's One to Many letter campaign?

One to Many is the internal name HMRC uses for campaigns where the same letter is sent to many taxpayers at once, based on a shared characteristic identified through data-matching, rather than tailoring correspondence to each individual case from the start. It is a cost-effective way for HMRC to prompt a large group to self-review.

You might receive one because your name appeared in Land Registry data as owning a rental property, in marketplace data as a frequent online seller, or in Common Reporting Standard data as holding an overseas account, without HMRC being able to match that to your tax return.

There is no dedicated statute for One to Many letters; they are an administrative tool that HMRC uses within its general powers, informed by behavioural insight about how people respond to being told HMRC is already aware of an issue. The letter itself is usually not issued under a specific statutory information power such as Schedule 36 Finance Act 2008.

The consequence that does have statutory force is the effect on penalty treatment. Once a One to Many letter names the specific income or issue, a disclosure made afterwards is generally treated as prompted under Schedule 24 Finance Act 2007, sitting in a higher penalty range than the same disclosure made unprompted, before any letter arrived.

If a recipient does not respond, HMRC can escalate to a formal compliance check or Self Assessment enquiry under the Taxes Management Act 1970, at which point the full range of HMRC's information-gathering powers becomes available.

One to Many letters are typically addressed to individuals about personal tax matters, so as a director you should check carefully whether the letter concerns your personal Self Assessment position rather than your company.

Where the underlying issue touches both, such as dividends drawn from undisclosed rental profit routed through a personal account, review both the personal and company positions together before responding.

Because a One to Many letter names the specific issue, any subsequent disclosure is usually prompted, meaning a higher Schedule 24 penalty range than if you had come forward first. Acting promptly after receiving the letter still keeps costs lower than ignoring it and facing a formal enquiry.

If the matter develops into a formal enquiry, tax investigation insurance included with our Growth plans covers professional representation costs — see /fees.

Do not dismiss the letter as a mass mailing that does not really apply to you without checking your records against the specific issue it raises.

Avoid replying with a blanket denial before verifying your position properly, since an inaccurate response can attract more scrutiny than a considered one.

Do not delay a response once you have confirmed something is owed. Further delay after a named One to Many letter increases the risk of a formal enquiry with wider information-gathering powers.