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Advanced Taxation (UK) · Investment and other expenditure that reduces tax liabilities

Stamp Taxes, VAT and Interest and Penalty Rules for ATX-UK

Updated 11 October 2026 · Fact-checked

These are the small-rate-table taxes that ATX-UK tests inside bigger scenarios. SDLT on non-residential property is banded (0%, 2%, 5%). Stamp duty on shares is 0.5%. VAT has a 20% rate, £90,000 registration limit and £88,000 deregistration limit. Late VAT and tax interest use set percentages from the tax tables.

Understand Stamp Taxes, VAT and Interest and Penalty Rules

Most ATX-UK scenarios end with a cost or cash flow point. A property purchase has SDLT. A share purchase has stamp duty. A growing business may need to register for VAT. A late payment brings a penalty or interest. You rarely get a whole question on these, but you lose easy marks if you ignore them.

SDLT on non-residential property is charged in slices, like income tax. In the tables, the first £150,000 is at 0%, the next slice from £150,001 to £250,000 is at 2%, and anything above £250,000 is at 5%. You tax each slice at its own rate. You do not apply one rate to the whole price.

Stamp duty on shares is a flat 0.5% of the consideration. It is paid by the buyer. It applies to shares, not to land. Do not mix it with SDLT.

VAT has a standard rate of 20%. A trader must register when taxable turnover exceeds the registration limit of £90,000. A registered trader can apply to deregister when turnover is expected to fall below the deregistration limit of £88,000. The tables give the limits. The detailed timing rules come from your TX-UK knowledge, so recap them.

Late VAT payment penalties depend on how late the payment is. Up to 15 days late: no penalty. 16 to 30 days late: 3%. More than 30 days late: 6%, plus a daily penalty at an annual rate of 10%.

Interest is charged at 8.50% on underpaid tax and paid at 3.50% on overpaid tax. These rates are assumed in the tables. The official rate of interest of 3.75% is used to value beneficial loans for employees. It is a different thing from interest on late tax. Pick the right rate for the right situation.

Key rules to remember

SDLT on non-residential property
0% on first £150,000; 2% on £150,001 to £250,000; 5% above £250,000
Slice rates. Tax each band separately and add.
Stamp duty on shares
Stamp duty = 0.5% × consideration
Paid by the buyer. Do not use for land.
VAT standard rate
VAT = 20% × net value; VAT-inclusive price ÷ 1.2 = net value
Use ÷ 1.2 to strip VAT from a gross figure.
VAT registration and deregistration limits
Register above £90,000; deregistration limit £88,000
Read the scenario for the turnover test and dates.
Late VAT payment penalty
Up to 15 days: nil; 16 to 30 days: 3%; over 30 days: 6% plus daily penalty at 10% a year
Apply to the unpaid VAT.
Interest on tax
Underpaid: 8.50%; overpaid: 3.50%
Interest = tax × rate × days ÷ 365, or months ÷ 12.
Official rate of interest
3.75%
Used for beneficial loans, not for late tax.

How to solve Stamp Taxes, VAT and Interest and Penalty Rules questions

Use this method for any question that touches stamp taxes, VAT, penalties or interest.

  1. 1Identify which tax applies: land (SDLT), shares (stamp duty), VAT, or interest and penalty.
  2. 2Check the asset is non-residential property for SDLT. Do not apply SDLT to shares.
  3. 3Open the tax tables and find the correct rate or limit. Do not rely on memory.
  4. 4Compute by slices for SDLT, and by flat rate for stamp duty and VAT.
  5. 5For late payment, count the days late and pick the penalty band. Apply it to the unpaid amount.
  6. 6For interest, choose the underpaid (8.50%), overpaid (3.50%) or official (3.75%) rate, and time-apportion.
  7. 7State the amount, who pays it and the effect on cash flow or on the decision asked.

Quickest way: Rate-and-band shortcut

When to use it: Use this when the question asks for a quick cost of a purchase or a penalty.

  1. For SDLT above £250,000, use this: £2,000 + 5% × (price − £250,000). The £2,000 is 2% of the £100,000 middle slice.
  2. For price between £150,000 and £250,000, use 2% × (price − £150,000).
  3. For stamp duty, multiply the price by 0.005.
  4. For a VAT-inclusive figure, divide by 1.2 to get net and subtract to get VAT.
  5. For interest, tax × rate × months ÷ 12.

Common mistakes in Stamp Taxes, VAT and Interest and Penalty Rules

  • Applying 5% to the whole price for SDLT.

    Students treat the rates as a single flat rate.

    Fix: Tax each slice at its own rate. The first £150,000 is at 0%.

  • Charging SDLT on a share purchase or stamp duty on land.

    Both are called stamp taxes, so they blur together.

    Fix: SDLT is for land. Stamp duty is for shares at 0.5%.

  • Using the official rate of 3.75% for late tax interest.

    Both are interest rates in the tables.

    Fix: Use 8.50% for underpaid tax and 3.50% for overpaid tax. The official rate is for beneficial loans.

  • Charging a penalty when VAT is up to 15 days late.

    Students assume every late payment is penalised.

    Fix: There is no penalty up to 15 days. Count days carefully.

  • Forgetting the daily penalty when VAT is more than 30 days late.

    Only the 6% figure is remembered.

    Fix: State 6% plus a daily penalty at an annual rate of 10%.

  • Mixing the VAT registration and deregistration limits.

    The two figures are close together.

    Fix: Register above £90,000. The deregistration limit is £88,000.

Worked examples

Example 1

A company buys a warehouse (non-residential) for £420,000. Calculate the SDLT payable.

Show the solution
  1. First £150,000 at 0% = £0.
  2. Next £100,000 (£150,001 to £250,000) at 2% = £2,000.
  3. Remaining £170,000 (£420,000 − £250,000) at 5% = £8,500.
  4. Total = £0 + £2,000 + £8,500 = £10,500.

Answer: SDLT payable is £10,500.

Example 2

A trader pays VAT of £12,000 which is 20 days late. Later, the trader finds that corporation tax of £30,000 was underpaid and settles it 6 months after the due date. State the VAT penalty and the interest on the corporation tax.

Show the solution
  1. 20 days late falls in the 16 to 30 day band, so the penalty is 3%.
  2. VAT penalty = 3% × £12,000 = £360.
  3. Interest on underpaid tax is 8.50%.
  4. Interest = £30,000 × 8.50% × 6 ÷ 12 = £1,275.

Answer: VAT penalty is £360 and interest on the underpaid corporation tax is £1,275.

Exam tips

  • Always open the tax tables and read the rate. Marks go for using the right figure.
  • Show SDLT by slice on separate lines so the marker can follow your working.
  • Say who pays: the buyer pays stamp duty and SDLT.
  • Label interest clearly as underpaid, overpaid or official rate, and say why.
  • When a plan changes a payment date, link it to the interest or penalty effect to earn the commercial points.

Practice questions from Investment and other expenditure that reduces tax liabilities

Stamp Taxes, VAT and Interest and Penalty Rules in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Stamp Taxes, VAT and Interest and Penalty Rules: frequently asked questions

What are the SDLT rates for non-residential property in ATX-UK?

They are given in the tax tables: 0% up to £150,000, 2% from £150,001 to £250,000 and 5% above £250,000. They apply to each slice of the price.

How much is stamp duty on shares?

It is 0.5% of the price paid. It applies to share purchases, not to land.

What are the VAT registration and deregistration limits?

The registration limit is £90,000 and the deregistration limit is £88,000. The standard VAT rate is 20%.

What is the penalty for late VAT payment?

There is no penalty up to 15 days late. At 16 to 30 days it is 3%. Over 30 days it is 6% plus a daily penalty at an annual rate of 10%.

Which interest rate do I use for late tax?

Use 8.50% for underpaid tax and 3.50% for overpaid tax. The 3.75% official rate is for beneficial loans to employees.