What sources does Taxxa search?

Taxxa searches a continuously updated collection of more than one million pages from tax authorities, government publications, legislation and case law across the European jurisdictions it covers. Every response cites the underlying material, so a professional can inspect the rule, its jurisdiction and whether it is current before relying on the result.

Can Taxxa work with a team’s own documents?

Yes. Research can combine the public knowledge base with a team’s own PDF, DOCX, CSV and TXT files in one workspace. That makes it possible to compare a client document with the relevant guidance, trace a conclusion to its source and prepare a draft without losing the evidence that supports it.

Who is Taxxa built for?

Accountants, auditors, tax advisors, payroll specialists, bookkeepers and advisory teams working across European jurisdictions. Shared workspaces keep research available to colleagues, and citations make review easier.

Where is customer data stored, and is it used to train models?

Customer data stays in the European Union and is never used to train language models.

Does Taxxa replace professional judgement?

No. Taxxa is a research and drafting workspace. It helps professionals reach an informed starting point faster; the professional still reviews the evidence and makes the final decision. It does not file returns, post bookkeeping entries or give legal advice.

United KingdomGOV.UK

HMRC directs SDLT scheme-reference notifications to the postal form

AAG4(SDLT) users must complete the interactive postal form in Adobe Reader; HMRC’s broader disclosure guide still refers to an electronic option.

By Taxxa AI OyPublished 20 August 2026

Tax

People who expect a Stamp Duty Land Tax advantage and have received an eight-digit scheme reference number are now directed to notify HMRC using the postal AAG4(SDLT) formGOV. The form-specific instructions have removed the previous choice between online and postal versionsGOV. This changes the submission route described for the notification, while retaining the same stated conditions for using the form.

The eight-digit reference number may have been received from any of the following:

- HMRC - a scheme promoter - a person involved in the supply of the arrangements - the client of a scheme promoter Advisers should therefore check both the expected SDLT advantage and receipt of the number when deciding whether these instructions apply. Receipt directly from HMRC is one of the listed cases, rather than the only route by which the taxpayer may have obtained the number.

The postal form remains interactive: it is completed on screen, and HMRC says Adobe Reader must be used to complete itGOV. On-screen completion should not be confused with the online submission option that has been removedGOV. The current form-specific instruction is to report the scheme reference number using the postal versionGOV.

There is a conflict with HMRC’s broader Forms to disclose tax avoidance schemes guidanceGOV. Its SDLT section still describes notification electronically or by post using AAG4(SDLT)GOV, whereas the form-specific instructions now describe the postal routeGOV. Practitioners preparing this notification should use the form-specific postal instructions rather than rely on that general electronic-submission reference.

AAG4(SDLT) reports a scheme reference number to HMRCGOV. The general guidance separately identifies AAG6 as the form promoters use to provide a reference number to a clientGOV. These are different communications: giving a client the number is distinct from the client’s notification to HMRC.

Anyone having difficulty opening or saving the postal form is directed to the Online Services Helpdesk. HMRC also invites requests by email for the form in Welsh; that invitation concerns obtaining the Welsh form.

HMRC sets out the form’s scope and completion requirements in Tell HMRC your Stamp Duty Land Tax scheme reference number.

If you expect an SDLT advantage and have received an eight-digit scheme reference number, complete AAG4(SDLT) in Adobe Reader and submit the postal form to HMRC.

Sources