IDG52200 - Information disclosure Gateways with other government departments: HM Treasury (HMT)
Source: gov.uk (2025-07-21)


Why share information with His Majesty’s Treasury (HMT)

The policy partnership between HMRC and HMT is a key relationship in the design and delivery of tax policy. Within the partnership, HMT, supported by HMRC, leads on strategic work and policy development: HMRC, supported by HMT, leads on the maintenance and delivery of existing tax policy. Although sharing HMRC information with HMT may be beneficial to the development, maintenance and delivery of tax policy, such disclosure is still subject to HMRC’s duty of confidentiality and must only be made where you have lawful authority.

Ensuring information is shared lawfully

There is no information-sharing gateway that enables HMRC to lawfully disclose HMRC information to HMT, so information can only be shared where there is another lawful means for disclosure, such as with the customer’s consent or where the disclosure is relevant to HMRC’s own functions.

Anonymised information

Anonymised information may be disclosed to HMT where it would aid the development or maintenance of policy, or explain HMRC policy or operational decisions.

Such disclosures will generally be necessary, expedient, incidental or conducive to the exercise of HMRC’s functions. See IDG40400 (https://www.gov.uk/hmrc-internal-manuals/information-disclosure-guide/idg40400) for further guidance.

Customer specific information

It is generally unlikely that any disclosure to HMT will require the identification of individual companies or persons. In most cases it should be possible to give an outline of the policy issue without disclosing details of specific HMRC customers.

However, if a policy issue needs to be discussed with HMT where the circumstances involved are so specific that it would be quite clear to any person with knowledge in the area that they could only apply to one individual, you should disclose the information necessary to enable the policy issue to be addressed. This may include details of the individual HMRC customer.

You should be satisfied before making the disclosure that it is necessary for the functions of HMRC. The relevant test is whether the disclosure supports HMRC’s own functions, not HMT’s, but bearing in mind that one of HMRC’s functions is to deliver effective policy advice to HMT, in support of the policy partnership.

See IDG40400 (https://www.gov.uk/hmrc-internal-manuals/information-disclosure-guide/idg40400) for more information on disclosures which are necessary for HMRC’s own functions.

Consent

There may be occasions where an individual consents to HMRC providing information to HMT. In such a case, you must ensure that the consent is freely given, is in writing and clearly sets out what information may be disclosed. For further information see IDG30210 (https://www.gov.uk/hmrc-internal-manuals/information-disclosure-guide/idg30210).

Public domain

Information already lawfully in the public domain may be provided to HMT.

Interchange

Treasury officials who spend time working in HMRC are bound by the same duty of confidentiality as HMRC officers. They must not unlawfully disclose any HMRC information that they obtain or access, either whilst working for HMRC or after returning to HMT. Any unlawful disclosures will be treated in the same manner as an unlawful disclosure by a member of HMRC and may be subject to disciplinary action or criminal sanctions (see IDG40130 (https://www.gov.uk/hmrc-internal-manuals/information-disclosure-guide/idg40130)).

Similarly, any HMRC officer that spends time working in HMT must not disclose any HMRC information to HMT colleagues unless they have lawful authority to do so.

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Ministerial correspondence

Ministerial correspondence consists of letters (and sometimes e-mails) from MPs (or other elected representatives) to Ministers and may either be a letter from an MP on behalf of a constituent or a copy of a constituent's letter to the MP. All such correspondence is initially sent to the Correspondence and Enquiry Unit (CEU) based in HMT. CEU will advise how Ministerial correspondence should be dealt with.

See IDG30440 (https://www.gov.uk/hmrc-internal-manuals/information-disclosure-guide/idg30440) for further guidance on disclosing customer information in correspondence with MPs.

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Further guidance

If you receive a request for information and are unsure how to proceed please contact your Security Information & Business Partner (SIBP).