Making Tax Digital Calculator for Landlords

Multiple Dwellings Relief (MDR) Calculator – estimate SDLT and potential savings

If you are buying more than one residential unit in a single deal, you have probably searched for a Multiple Dwellings Relief calculator or an MDR SDLT calculator. Landlords use MDR maths to sanity-check Stamp Duty Land Tax (SDLT) when they are buying a pair of flats, a small property portfolio, or a house with a self-contained annex.

The August Multiple Dwellings Relief (MDR) calculator lets you compare SDLT with and without MDR, using the average price per dwelling method and a minimum “floor”. Enter the total purchase price and number of dwellings, choose whether higher rates for additional properties apply, then click Calculate.

Planning guidance only, this is not tax advice. Always check HMRC rules or speak to a qualified adviser.

Important: is Multiple Dwellings Relief still available?

In England and Northern Ireland, MDR has been abolished for transactions with an effective date on or after 1 June 2024.

There are transitional rules. MDR can still be available where the relevant contract was entered into or exchanged on or before 6 March 2024, provided conditions are met and the transaction is not excluded.

This is exactly why a calculator is still useful. You may be dealing with an older contract, a linked transaction, or you may simply want to understand how the MDR method compares to standard SDLT when reviewing historic numbers.

What this calculator does and why it’s different

This calculator is designed for quick clarity to help you make decisions faster:

It shows standard SDLT on the total purchase price, then shows the MDR method (SDLT on the average dwelling price, multiplied by the number of dwellings), and it highlights any implied saving after the minimum MDR floor.

It includes an additional property (higher rates) toggle, which is the reality for most buy-to-let acquisitions.

It gives a band-by-band breakdown, so you can see where the tax is coming from rather than trusting a single headline number.

If you want a broader SDLT view across buyer types and switches (including non-resident surcharge and mixed-use), use the August Stamp Duty calculator.

How Multiple Dwellings Relief works

When MDR applied, the steps were:

You take the total purchase price for all dwellings.

You divide by the number of dwellings to get an average price per dwelling.

You calculate SDLT on that average price using the residential SDLT bands.

You multiply the SDLT by the number of dwellings.

You apply the minimum MDR floor if relevant, this is commonly 1% of the total price.

In plain terms, MDR tended to help when the combined price pushed you into higher SDLT bands, but the average dwelling price stayed in lower bands.

Inputs and assumptions

The calculator keeps inputs minimal so it is fast to use:

Total purchase price: the combined consideration for all dwellings.

Number of dwellings: used to calculate the average dwelling price.

Higher rates (additional property): toggle on if the higher rates apply.

Minimum MDR rate: the MDR “floor” percentage (editable).

Whether something counts as a “dwelling” can be specific, particularly for annexes and unusual layouts. Linked transactions can also change outcomes. If your deal hinges on definitions, it is worth taking advice early.

Worked example

You buy two dwellings for £600,000 total. The average price per dwelling is £300,000.

Standard SDLT is calculated on the full £600,000.

The MDR method calculates SDLT on £300,000, then multiplies it by two, and applies the minimum floor if needed.

The calculator shows both results side by side, plus any saving, so you can see whether the MDR method is meaningful for your deal.

How to use the August MDR calculator

Enter the total purchase price and number of dwellings.

Set higher rates to match your buyer position.

Adjust the minimum MDR rate if your planning scenario needs it.

Click Calculate to see SDLT with and without MDR and the band breakdown.

Keep the rest of the deal tidy in August

Once you have bought, you still need clean records and evidence. Store contracts, certificates and invoices in Documents, and keep on top of deadlines using August’s compliance tooling and templates, starting with the free Landlord Checklist.

Related August calculators

If you are modelling a purchase, these usually sit alongside MDR calculations:

Stamp Duty calculator - Buyer types, surcharges, mixed-use toggles
UK Property Lookup - EPC, council tax band, sold prices
Buy-to-Let Mortgage calculator - Repayments, LTV, stress-testing
Rental Cashflow calculator - Monthly net cashflow
Rental Yield calculator - Gross and net yield
Main calculators page

Disclaimer

The Multiple Dwellings Relief (MDR) Calculator is for general information and planning only. It uses simplified assumptions and editable settings. We cannot guarantee calculations are complete, current, or accurate for every landlord, property, or transaction.

This tool is not tax advice and is not a substitute for HMRC guidance or professional advice. SDLT outcomes can vary based on timing (exchange, completion, substantial performance), buyer circumstances, linked transactions, mixed use, and whether units meet the definition of a dwelling. Always consult HMRC resources and a qualified adviser before filing or relying on a relief position.