Stamp Duty Legal Hub
HMRC compliance, case law, anti-avoidance rules, and tax tribunal procedures for SDLT. Getting the legal side right protects you from penalties. Getting it wrong can cost far more than the original tax bill.
HMRC & Compliance
SDLT Return Requirements
Who must file, forms, and the SDLT5 certificate process
14-Day Deadline & Penalties
Filing deadlines, late penalties, and interest charges
HMRC Enquiry Process
9-month enquiry window, compliance checks, and record-keeping
Stamp Duty Disputes
Internal review, ADR mediation, and challenging assessments
Tax Tribunal Appeals
First-tier Tribunal, Upper Tribunal, and Court of Appeal
Substantial Performance
Triggers SDLT before completion: occupation, 90% payment, or lease commencement
Legal Precedents & Cases
Landmark Stamp Duty Cases
Key decisions including Tower One v HMRC and s75A rulings
MDR Case Law
Multiple Dwellings Relief abolition and transitional cases
Mixed-Use Classification Cases
Residential vs non-residential disputes and HMRC crackdowns
Additional Dwelling Surcharge Cases
5% surcharge disputes, replacement rules, and refund claims
Connected Party & Linked Transactions
Linked transaction rules, aggregation, and tribunal decisions
Your SDLT Obligations: Timeline
From completion to the HMRC enquiry window, understanding the key dates in the SDLT lifecycle helps you stay compliant and avoid costly mistakes.
Effective date (completion)
SDLT return clock starts. Instruct your solicitor to prepare the SDLT1 form.
SDLT filing deadline
SDLT return must be filed AND tax paid by this date. Late filing triggers automatic £100 penalty.
Late filing penalties begin
£100 automatic penalty. Interest accrues on unpaid tax at HMRC's standard rate (currently 7.25% p.a.).
Penalty escalates
Late filing penalty rises to £200. Daily penalties may also begin if HMRC issues a notice.
HMRC enquiry window
HMRC can open a compliance check within 9 months of the filing deadline for routine cases.
Amendment window closes
Buyers can amend SDLT returns within 12 months of filing. After this, errors require HMRC correction.
Penalty Summary
Late filing and incorrect returns attract fixed and tax-geared penalties. These are separate from the interest charged on any unpaid tax.
| Trigger | Penalty | Interest Charged? |
|---|---|---|
| Filed 1 day late | £100 flat | Yes |
| Filed 3+ months late | £200 flat | Yes |
| HMRC issues daily penalty notice | Up to £10/day | Yes |
| Fraudulent or negligent return | Up to 100% of tax due | Yes |
| Offshore non-disclosure | Up to 200% of tax due | Yes |
High-Risk Areas Under HMRC Scrutiny
HMRC targets specific categories of SDLT return where it believes non-compliance is widespread. If your purchase falls into one of these areas, ensure it is well documented.
Mixed-use classification
Claiming commercial rates on a property with any residential element. HMRC has specifically targeted this following a rise in questionable claims.
Multiple dwellings annex claims
Claiming MDR or annexe rules for properties that do not meet HMRC's tests. Now one of the most heavily scrutinised claim categories.
Additional dwelling surcharge avoidance
Using trust structures or nominee arrangements to avoid the 5% surcharge. HMRC uses s75A to look through such arrangements.
Linked transaction under-reporting
Splitting purchases to keep each below a rate threshold. Transactions with the same buyer and seller are automatically linked under s108 FA 2003.
April 2025 Changed Everything
The nil-rate band dropped from £250,000 to £125,000, the additional dwelling surcharge rose from 3% to 5%, and first-time buyer thresholds were significantly reduced. Every legal topic in this section includes before/after comparison tables showing how these changes affect compliance, disputes, and planning.