Buyer-type calculator
Transfer of Equity Stamp Duty Calculator 2025 - 26
Use this transfer of equity stamp duty calculator when adding a partner, removing a co-owner, buying out a share, or transferring ownership of a mortgaged home. Unlike the standard stamp duty calculator, this page does not tax the full property value. It calculates SDLT on the share of mortgage debt being assumed, subject to context and exemptions.
In short
You pay stamp duty on a transfer of equity only if there is chargeable consideration, such as taking on part of an outstanding mortgage or paying cash for the share. The SDLT is calculated on that consideration, not the full property value. Court-ordered divorce and separation transfers are generally exempt.
Transfer of equity stamp duty calculator inputs
This page needs custom logic, not the standard price-only calculator. The inputs should be property value, outstanding mortgage, percentage being transferred to the buyer, context and jurisdiction. The default example should be a £400,000 property with a £200,000 mortgage and a 50% transfer.
| Input | Default | Why it matters |
|---|---|---|
| Property value | £400,000 | Used for comparison with a normal purchase, not the main SDLT calculation. |
| Outstanding mortgage | £200,000 | Mortgage liability can be chargeable consideration. |
| Percentage being transferred to you | 50% | Determines the share of mortgage debt assumed. |
| Context | Adding partner | Divorce/court-order transfers may be exempt. |
| Jurisdiction | England only | Scotland and Wales use equivalent but separate LBTT/LTT provisions. |
Production improvement: add an optional cash consideration input because HMRC treats cash paid for equity as chargeable consideration too.
Why SDLT is calculated on the mortgage share, not the property value
In a transfer of equity, the taxable amount is the chargeable consideration given for the share. Where no cash changes hands, the common source of consideration is the mortgage liability taken on by the incoming or remaining owner. The simplified calculator formula is: outstanding mortgage × percentage being acquired. If the outstanding mortgage is £0 and there is no cash payment, the SDLT result is usually £0.
| Formula element | Example value | Result |
|---|---|---|
| Outstanding mortgage | £200,000 | Debt attached to the property |
| Percentage being acquired | 50% | Incoming buyer's mortgage share |
| Chargeable consideration | £200,000 × 50% | £100,000 |
Do not calculate on the full market value unless the transfer is to/from a connected company or another special rule applies.
Common transfer of equity scenarios
Adding a partner usually means both names go on the title and mortgage; SDLT can apply if the partner takes on mortgage debt. Removing a partner in a buyout can trigger SDLT for the person taking over the loan. Divorce is different: a court-ordered or qualifying divorce-related transfer is generally exempt. A remortgage only, with no name change on the title, is not a transfer of equity and should not trigger this calculator.
| Scenario | Likely SDLT treatment | Calculator behaviour |
|---|---|---|
| Adding partner | Tax on mortgage share and any cash consideration if above threshold | Use formula. |
| Removing partner / buyout | Tax on mortgage share taken over plus any cash paid | Use formula and warn about cash input. |
| Divorce or court order | Generally exempt | Show exemption banner and £0 estimate. |
| Remortgage only | No transfer of equity | Route away from calculator. |
The context radio buttons should change the explanation as well as the tax result.
Worked example: £400,000 property, £200,000 mortgage, 50% transfer
The chargeable consideration is £200,000 × 50% = £100,000. That is below the £125,000 SDLT threshold, so the SDLT due is £0. If this were a normal £400,000 purchase, standard SDLT would be £10,000.
| Step | Calculation | Result |
|---|---|---|
| Mortgage share | £200,000 × 50% | £100,000 |
| Apply SDLT bands | Chargeable consideration below £125,000 | £0 |
| Full purchase comparison | Standard SDLT on £400,000 | £10,000 |
This is the default calculator scenario and should be used in the meta description and FAQ.
Worked example: £600,000 property, £350,000 mortgage, 50% transfer
The chargeable consideration is £350,000 × 50% = £175,000. SDLT is £1,000, calculated as 0% on £125,000 and 2% on the remaining £50,000. A standard full purchase at £600,000 would cost £20,000.
| Step | Calculation | Result |
|---|---|---|
| Mortgage share | £350,000 × 50% | £175,000 |
| Apply SDLT bands | 0% on £125,000 + 2% on £50,000 | £1,000 |
| Full purchase comparison | Standard SDLT on £600,000 | £20,000 |
This example shows why chargeable consideration, not market value, is the critical input.
Divorce, separation and court-order transfers
If the context selected is Divorce/separation, the calculator should first ask whether the transfer is made under a court order or qualifying agreement connected with divorce, dissolution, annulment or legal separation. If yes, show a prominent exemption note and a £0 SDLT result. If the transfer is consensual and outside the qualifying exemption, SDLT may still apply based on mortgage debt and cash consideration.
Prominent note: 'Court-ordered transfers between divorcing spouses are exempt from SDLT.'
Scotland and Wales equivalents
The calculator should be labelled England only because SDLT applies in England and Northern Ireland. Scotland and Wales have equivalent provisions under LBTT and LTT, but the rates, filings and authorities differ. The page should link to LBTT and LTT calculators and state that the same conceptual issue applies: tax is based on chargeable consideration, not automatically the full property value.
Jurisdiction note: do not present this as UK-wide legal advice.
Estimate SDLT on the mortgage share before you instruct a solicitor or agree a partner buyout.
Calculate My Stamp Duty →Frequently Asked Questions
You may pay SDLT on a transfer of equity if the person receiving the share gives chargeable consideration, such as taking responsibility for part of the mortgage. If there is no mortgage and no cash payment, there is usually no SDLT.
The SDLT is £0 if the only consideration is taking on 50% of a £200,000 mortgage. The chargeable consideration is £100,000, which is below the £125,000 residential SDLT threshold.
The SDLT is £1,000 if the only consideration is taking on 50% of a £350,000 mortgage. The chargeable consideration is £175,000, so 2% is charged on the £50,000 above the £125,000 threshold.
You usually do not pay SDLT on a transfer of equity with no mortgage if no money or other chargeable consideration changes hands. A genuine gift with no mortgage liability is normally outside SDLT.
A transfer between divorcing or separating spouses or civil partners is generally exempt from SDLT when made under an agreement or court order connected with the divorce, dissolution, annulment or legal separation.
You may pay SDLT when adding a partner if they take responsibility for part of the outstanding mortgage or pay cash for equity. The taxable amount is the chargeable consideration, not automatically the full market value.
The person taking over the other person's share may pay SDLT if they take on mortgage liability or pay cash consideration above the SDLT threshold. Divorce and court-order transfers may be exempt.
No, shared ownership SDLT uses different rules, including market value election and staircasing rules. This transfer of equity calculator should only handle ownership-share transfers in an existing mortgaged property.
Related stamp duty pages
- second home stamp duty calculator
Cross-link where ownership transfers create additional-property questions.
- stamp duty rates
Reference current SDLT band rates used after chargeable consideration is calculated.
- what is stamp duty
Definition page for users new to SDLT.
- first-time buyer stamp duty calculator
Route shared ownership and first home questions.
- main UK stamp duty calculator
Required all-mode calculator link.
- LTT calculator Wales
Jurisdiction-specific equivalent for Wales.