SDLT Deadlines & Penalties

Key facts

The SDLT return must be filed within 14 days of the effective date (usually completion).
The SDLT payment is also due within 14 days — the same deadline as the return.
Late filing attracts an automatic £100 penalty, rising for longer delays.
Interest is charged on late payment from the due date until the date of payment.
Penalties can be appealed if you have a reasonable excuse.

The 14-Day Deadline

Both the SDLT return and the SDLT payment are due within 14 days of the effective date of the transaction. The effective date is usually the date of completion — the day you pay the balance and ownership transfers.^[2]

This deadline was reduced from 30 days to 14 days with effect from 1 March 2019, giving buyers significantly less time to file.

In practice: Your solicitor will normally file the SDLT return and arrange payment on or shortly after completion day. Most solicitors ensure the return is filed within a few days of completion to avoid any risk of penalties.

Late Filing Penalties

If the SDLT return is filed late, HMRC imposes automatic penalties:^[1]

How Late	Penalty
Up to 3 months late	£100 (automatic)
3 – 6 months late	£200 (automatic)
6 – 12 months late	£200 plus a tax-related penalty (up to the amount of tax due)
More than 12 months late	£200 plus a tax-related penalty of up to 100% of the tax due

The tax-related penalty for returns that are more than 12 months late depends on the purchaser’s behaviour:

Reasonable care taken — penalty may be nil
Careless behaviour — up to 30% of the tax due
Deliberate failure — up to 70% of the tax due
Deliberate and concealed — up to 100% of the tax due

Late Payment Interest

If the SDLT is not paid by the 14-day deadline, HMRC charges interest on the unpaid amount from the due date until the date of payment.^[1]

Key points:

Interest is charged at the HMRC late payment interest rate (currently the Bank of England base rate plus 2.5%)
Interest runs from the filing deadline (14 days after the effective date) until the full amount is paid
Interest is charged automatically — there is no need for HMRC to issue a separate notice
Interest is not tax-deductible

Inaccuracy Penalties

If your SDLT return contains an inaccuracy that leads to an understatement of tax, HMRC may impose an inaccuracy penalty under Schedule 24 to the Finance Act 2007:^[3]

Type of Inaccuracy	Penalty Range
Careless	0% – 30% of the additional tax due
Deliberate but not concealed	20% – 70% of the additional tax due
Deliberate and concealed	30% – 100% of the additional tax due

The penalty can be reduced if the purchaser makes a full disclosure and cooperates with HMRC.

Reasonable Excuse

You can appeal against a late filing or late payment penalty if you have a reasonable excuse. HMRC considers each case individually, but examples of reasonable excuses include:^[1]

Serious illness or death of the purchaser, their partner, or their solicitor
Unexpected hospital stay around the filing deadline
HMRC’s online filing system being unavailable (with evidence)
Fire, flood, or other natural disaster destroying records

The following are generally not accepted as reasonable excuses:

Not knowing the rules or the deadline
Relying on another person (e.g. a solicitor) who let you down — though this may be grounds for a professional negligence claim against the solicitor
Having insufficient funds to pay the SDLT

Tip: If your solicitor fails to file the SDLT return on time and you receive a penalty, you should ask the solicitor to pay the penalty and any interest, as it resulted from their delay. You may also wish to notify the Legal Ombudsman if the issue is not resolved.

How to Appeal a Penalty

To appeal an SDLT penalty:

Write to HMRC within 30 days of the penalty notice, explaining your reasonable excuse
Provide supporting evidence (e.g. medical certificates, hospital letters)
If HMRC rejects the appeal, you can request a statutory review
If the review is unsuccessful, you can appeal to the First-tier Tribunal (Tax Chamber)

Frequently Asked Questions

How long do I have to pay SDLT?

You must pay SDLT within 14 days of the effective date of the transaction (usually the date of completion). Your solicitor normally arranges payment on or before the completion date.

What happens if I file my SDLT return late?

If the return is up to 3 months late, there is an automatic penalty of £100. If it is more than 3 months late, the penalty increases to £200. For returns more than 12 months late, HMRC may impose a tax-related penalty of up to 100% of the tax due.

Can I appeal an SDLT penalty?

Yes. You can appeal if you have a reasonable excuse for the late filing or payment — for example, a serious illness, a death in the family, or an unexpected event outside your control. Being unaware of the deadline is generally not accepted as a reasonable excuse.

Is interest charged on late SDLT payments?

Yes. HMRC charges interest on unpaid SDLT from the date the tax was due (14 days after the effective date) until the date payment is received. The interest rate is set by HMRC and currently aligns with the Bank of England base rate plus 2.5%.

Sources

Stamp Duty Land Tax: penalties for late filing and late payment — GOV.UK
Stamp Duty Land Tax: filing your return — GOV.UK
SDLTM86000 – Compliance: penalties — HMRC