SDLT Return Requirements
Complete guide to filing SDLT returns with HMRC. Understand who must file, which forms to use, filing deadlines, and the critical changes from April 2025.
In this article
When you buy a property or land in England or Northern Ireland, you must submit a Stamp Duty Land Tax (SDLT) return to HM Revenue & Customs (HMRC), even if no tax is due. Understanding the filing requirements, forms, deadlines, and exemptions is crucial to avoid penalties and ensure compliance. This guide explains everything you need to know about SDLT return requirements, including the significant changes introduced in April 2025.
Who Must File an SDLT Return?
An SDLT return must be filed for every notifiable transaction. A transaction is notifiable if:
- Any SDLT is payable – This includes the standard rates and the additional dwelling surcharge
- Purchase price exceeds the nil-rate band – Currently £125,000 for residential property (£300,000 for first-time buyers on properties up to £500,000)
- Non-residential or mixed-use property – Different thresholds apply (£150,000 for non-residential)
- Lease premiums or rent exceeds threshold – For new leases or lease assignments
- Exchange of property – Where the market value exceeds the threshold
Important Note
Even if you qualify for relief or exemption, you may still need to file a return to claim it. The buyer is responsible for filing the return and paying any SDLT due, typically through their solicitor or conveyancer.
SDLT Forms Explained
HMRC uses several forms for different types of SDLT transactions. Understanding which form applies to your situation is essential for proper compliance.
SDLT1 – Main Return Form
The primary form used for most residential and non-residential property purchases. Completed online via the HMRC SDLT portal or by solicitors using compatible software. This form captures all transaction details, parties involved, consideration paid, and SDLT calculation.
SDLT2 – Additional Vendor Details
Required when there are more than two sellers in the transaction. Provides space for additional vendor names and addresses that cannot fit on the SDLT1 form.
SDLT3 – Additional Purchaser Details
Required when there are more than two buyers. Similar to SDLT2 but captures additional purchaser information including names, addresses, and National Insurance numbers if applicable.
SDLT4 – Additional Property Details
Used when multiple properties are being acquired in a single transaction, or when the transaction involves complex land arrangements that require additional description.
SDLT5 – Certificate of Compliance
The most important document for completing your property purchase. Once HMRC processes your return and receives payment, they issue an SDLT5 certificate. Your solicitor must submit this to the Land Registry before they can register the property in your name.
Online vs Paper Filing
HMRC strongly encourages online filing through their digital SDLT service or via solicitor software. However, paper returns are still accepted in specific circumstances.
Online Filing (Recommended)
- ✓Faster processing (SDLT5 in 7-10 days)
- ✓Immediate confirmation of receipt
- ✓Built-in validation reduces errors
- ✓Automatic tax calculation
- ✓Secure payment integration
- ✓Digital record keeping
Paper Filing
- •Slower processing (3-4 weeks minimum)
- •Manual calculation required
- •Higher risk of errors or omissions
- •No immediate confirmation
- •Separate payment process required
- •Only for exceptional circumstances
Processing Times Matter
Paper returns can take 3-4 weeks to process, which may delay completion of your property purchase. Online submissions typically receive SDLT5 certificates within 7-10 working days. Most solicitors now file electronically as standard practice.
Before vs After April 2025: Key Changes
Significant changes to SDLT rates and thresholds came into effect in April 2025, affecting when returns must be filed and how much tax is due. Understanding these changes is crucial for recent and upcoming transactions.
Before vs After April 2025
| Rule | Before April 2025 | After April 2025 (Current) |
|---|---|---|
| Nil-Rate Band (Standard) | £250,000 | £125,000 |
| First-Time Buyer Threshold | £425,000 | £300,000 |
| First-Time Buyer Max Property | £625,000 | £500,000 |
| Additional Dwelling Surcharge | 3% on entire value | 5% on entire value |
| Filing Deadline | 14 days after completion | 14 days after completion (unchanged) |
| Return Amendment Window | 12 months from filing date | 12 months from filing date (unchanged) |
| Non-Residential Threshold | £150,000 | £150,000 (unchanged) |
Common SDLT Return Mistakes to Avoid
Many buyers and even some professionals make errors when filing SDLT returns. Here are the most frequent mistakes and how to avoid them:
Missing the 14-Day Deadline
Failing to file within 14 days of completion triggers automatic penalties. Even if no tax is due, the return must be filed on time. Late filing incurs an immediate £100 penalty, plus daily penalties after 3 months.
Incorrect Additional Dwelling Surcharge Calculation
The 5% surcharge applies to the entire purchase price, not just the amount above the threshold. Many buyers incorrectly believe it only applies incrementally. This is now a common error since the rate increased from 3% in April 2025.
Forgetting to Claim Reliefs
First-time buyer relief, multiple dwellings relief, and other exemptions must be explicitly claimed on the return. You cannot add them later without amending the return, which involves additional administration and potential delays.
Incorrect Property Value Declaration
The chargeable consideration includes not just the cash paid but also any debt assumed, goods or services exchanged, and sometimes even the value of works carried out. Failing to include all elements can trigger HMRC enquiries.
Assuming No Return Needed Below Threshold
Even if the purchase price is below £125,000, a return may still be required in certain circumstances, such as when transferring property between connected parties or claiming specific reliefs. Always check with your solicitor.
Using Wrong Property Classification
Misclassifying a property as residential when it is mixed-use (or vice versa) can result in incorrect tax calculations. Mixed-use properties follow non-residential rates, which are generally more favorable.
Exemptions from Filing an SDLT Return
In limited circumstances, you may not need to file an SDLT return. However, these exemptions are narrowly defined and should always be verified with a qualified professional.
- No chargeable consideration – True gifts with no consideration (rare, as even £1 triggers reporting if above thresholds)
- Exempt transactions – Such as certain property transfers on divorce or dissolution of civil partnership
- Transactions not involving land – Sales of shares in property companies, for example, are not land transactions
- Variations of wills or intestacy – Within two years of death, if no consideration is given
- Property value below threshold AND no tax due – Must be under £40,000 (residential) or £150,000 (non-residential) with no tax liability
Important Warning
If you are unsure whether your transaction is exempt from SDLT filing requirements, always consult with a qualified solicitor or conveyancer. Incorrectly assuming an exemption applies can result in significant penalties, interest charges, and delays in registering your property with the Land Registry.
Summary: SDLT Return Filing Essentials
Filing an SDLT return is a mandatory part of most property transactions in England and Northern Ireland. The 14-day deadline is strict, and online filing is the fastest and most reliable method. The April 2025 changes significantly reduced the nil-rate band and increased the additional dwelling surcharge, meaning more transactions now require returns and higher tax bills are common.
Work closely with your solicitor or conveyancer to ensure your SDLT return is accurate, filed on time, and claims all applicable reliefs. The SDLT5 certificate is essential for completing your Land Registry registration, so any delays in filing can hold up the entire purchase process.
For complex transactions, multiple properties, or if you are unsure about your obligations, professional advice is invaluable in avoiding costly mistakes and ensuring full compliance with HMRC requirements.
Calculate Your Stamp Duty
Use our free calculator to determine your SDLT liability, including the additional dwelling surcharge and first-time buyer relief, based on current rates.
Calculate NowEmma Richardson, MRICS
Chartered Surveyor & Property Tax Specialist
Emma Richardson is a RICS-qualified Chartered Surveyor with over 12 years of experience in UK property taxation. She founded Stamp Duty Calculator to help buyers understand the complex world of property transaction taxes.