UK HMRC has published guidance on reporting cross-border arrangements under the new Mandatory Disclosure Rules. The new rules were recently introduced through the International Tax Enforcement (Disclosable Arrangements) Regulations 2023, which are based on the OECD's Model Mandatory Disclosure Rules for CRS Avoidance Arrangements and Opaque Offshore Structures (previous coverage). Reporting under the new rules will not be available until they enter into force on 28 March 2023. Until then, the prior DAC6 reporting rules continue to apply, although the scope of reporting in the UK under these rules was limited following the UK's withdrawal from the EU. Separate guidance is provided for this purpose.

---

Guidance - Check if you need to tell HMRC about a cross-border arrangement (MDR)

Find out if you need to tell us about any reportable cross-border arrangements under the Mandatory Disclosure Rules (MDR).

If you are involved in a cross-border arrangement you may have to tell HMRC about it. This could include:

• transfers of funds from an account in one country to an account in another country
• putting funds in an offshore trust

You are involved in a cross-border arrangement when you design, promote or manage it. This also applies where you offer help, support and advice or take part in the arrangement.

Who needs to tell HMRC

You need to tell us about a cross-border arrangement that you are involved in, if one of the following applies:

• you are a resident in the UK
• your business has its place of management in the UK
• your business is incorporated or registered in the UK
• your business operates in a branch or office located in the UK

There are exemptions from reporting, for example, if you would breach legal professional privilege by disclosing it to us, or if someone else has already reported the information.

When to tell us

You must tell us within 30 days from either the day:

• after the arrangement is made available
• the arrangement started
• after you offered help, support or advice about the arrangement

You must use whichever of these instances happens first.

Arrangements you must report

You must tell us about any cross-border arrangement that is:

• a Common Reporting Standard (CRS) avoidance arrangement: check HMRC internal manual IEIM645010 (Hallmark D1) — Undermining reporting obligations for more information
• an 'opaque offshore structure': check HMRC internal manual IEIM645020 (Hallmark D2) — Obscuring Beneficial Ownership for more information

If you do not report your arrangement you may have to pay a penalty. Read HMRC internal manual IEIM660000: Penalties for more information.

If you have any queries, email: enquiries.aeoi@hmrc.gov.uk.

How to tell us

You cannot currently report Mandatory Disclosure Rules. We will update this guidance to let you know how to report.

The deadline for reporting an arrangement that was made available from 25 June 2018 but was not reportable under DAC6 is 24 September 2023.

You can report arrangements that were made available, started, or where help, support or advice was provided on or after 28 March 2023.

You can still tell us about a cross-border arrangement for DAC6 — if the arrangement has not yet been reported.

More information

You can also check the cross-border arrangements schema and supporting documents you'll need for reporting under Mandatory Disclosure Rules.