Summary
- From 1 April 2026, HMRC allows businesses to register as VAT IOSS intermediaries, enabling them to register clients, file monthly IOSS returns, and pay import VAT on clients’ behalf. [gov.uk], [gov.uk]
- Only businesses UK VAT‑registered and established in Northern Ireland may act as IOSS intermediaries, and they assume joint and several liability for VAT due under the scheme. [gov.uk]
- Intermediaries must register themselves first, then separately register each client, submit monthly IOSS VAT returns, make a single monthly VAT payment, and retain records for 10 years. [gov.uk], [vatfaqs.com]
Article
Background: Why the IOSS Intermediary Regime Matters
The VAT Import One Stop Shop (IOSS) is designed to simplify VAT compliance for distance sales of low‑value goods (≤ £135) imported from outside the EU and Northern Ireland to consumers within the EU and/or Northern Ireland. From 1 April 2026, businesses established outside the EU and Northern Ireland (including Great Britain) may only use the IOSS scheme if they appoint an approved intermediary. [icaew.com]
In response, HMRC has issued a comprehensive set of guidance confirming the operational framework for UK‑based IOSS intermediaries, aligning the UK with the EU IOSS intermediary model while reflecting Northern Ireland’s unique VAT position.
Who Can Act as an IOSS Intermediary?
To register as a VAT IOSS intermediary with HMRC, a business must:
- Be registered for UK VAT; and
- Have a business address in Northern Ireland. [gov.uk]
An intermediary may represent any number of clients, but each client may only be represented by one intermediary in Northern Ireland or an EU Member State at a time. Businesses previously excluded from the IOSS scheme must observe a two‑year cooling‑off period before re‑registration. [gov.uk]
Intermediary Responsibilities and Liability
Once registered, the intermediary becomes responsible for the full IOSS compliance cycle on behalf of its clients. This includes:
- Registering eligible clients for IOSS;
- Submitting monthly IOSS VAT returns covering all eligible sales;
- Making a single monthly VAT payment to HMRC; and
- Maintaining transactional records for 10 years, available electronically on request. [gov.uk], [vatfaqs.com]
Crucially, HMRC confirms that intermediaries are jointly and severally liable for the VAT due under the IOSS scheme, reinforcing the need for strong onboarding and monitoring controls. [gov.uk]
Registering as an Intermediary
Intermediaries must register themselves first via HMRC’s online service using their UK VAT credentials. Only once this registration is approved can they proceed to register individual clients. [gov.uk]
A business can only hold one active IOSS intermediary registration at any time. Where a business is already registered as an intermediary in an EU Member State, that registration must be cancelled before registering with HMRC. [gov.uk]
Registering Clients
After approval, intermediaries can add clients to their IOSS intermediary account. For each client, detailed information is required, including:
- Business identification and contact details;
- VAT or national tax numbers (where applicable);
- Prior IOSS or OSS registrations; and
- Online marketplaces or websites used for sales. [gov.uk]
HMRC stresses that intermediaries must use their own credentials, not the client’s, when performing client registrations.
Submitting IOSS VAT Returns
Intermediaries must submit a monthly IOSS VAT return for each client, even where no sales have taken place (nil returns). Returns must:
- Report VAT due on eligible imports to EU and Northern Ireland consumers;
- Use European Central Bank exchange rates for currency conversion; and
- Exclude sales outside the scope of IOSS (e.g. GB‑to‑NI domestic movements). [vatfaqs.com]
Errors can be corrected within three years of the original submission. Failure to submit returns for a prolonged period may result in cancellation of the client’s IOSS registration. [vatfaqs.com]
Practical Takeaway
These new HMRC services complete the UK’s IOSS intermediary framework just ahead of go‑live. For logistics providers, tax agents, marketplaces, and compliance service providers, the regime creates a significant operational role—but also meaningful compliance risk. Robust client due diligence, VAT determination processes, and return‑filing controls will be essential from 1 April 2026 onwards.
Source
- HMRC: Register your client to allow you to act as their intermediary for the VAT Import One Stop Shop scheme
- HMRC: Register to act as an intermediary for the VAT Import One Stop Shop scheme
- HMRC: Submit an Import One Stop Shop VAT return as an intermediary on behalf of your client
- HMRC: Check if you can register to act as an intermediary for the VAT Import One Stop Shop scheme
