Adding a Name to House Deeds: When SDLT Applies (and When It Doesn't)
In most cases adding a partner, spouse, civil partner, or adult child to your property deeds triggers no stamp duty at all. This guide explains the four scenarios where it does, and the timing rules around marriage that decide a £0 bill from a four-figure one.
Buying out an ex or paying cash for an equity share? You're on the wrong page.
That's a transfer of equity (buyout). The SDLT calculation is different and is fully covered in the transfer of equity complete guide . This page is about adding someone to the deeds as a gift, joint owner, or new spouse, where in most cases no SDLT is due.
Key Takeaways
- Adding a name to house deeds usually triggers no SDLT: the headline rule is that you only pay SDLT on chargeable consideration, and a pure gift between family members involves none.
- Transfers between spouses or civil partners are exempt regardless of any mortgage involved (s.73 Finance Act 2003), making the post-marriage timing critical.
- Adding an unmarried partner to a mortgaged property creates chargeable consideration equal to their share of the outstanding mortgage, and SDLT then depends on whether that figure crosses a rate band.
- A Declaration of Trust does not itself trigger SDLT because no legal title transfers, it only changes how the beneficial interest is recorded between existing owners.
- Even when no SDLT is due, an SDLT1 return is required within 14 days of completion if the consideration exceeds £40,000.
- For buyouts (cash + mortgage assumed in exchange for a defined equity share), the transfer of equity complete guide covers the SDLT mechanics in detail. That scenario sits outside the "adding a partner" framing covered here.
In this article
The short answer: usually no SDLT at all
Stamp duty (SDLT) is only triggered by “chargeable consideration”, meaning something of value passing in exchange for the share of ownership being transferred. When you add a partner, spouse, civil partner, adult child, or anyone else to your house deeds as a gift, no consideration changes hands. No consideration means no SDLT.
The complication is the mortgage. If the property is mortgaged and the person you are adding becomes jointly liable for that mortgage, HMRC treats the share of the debt they assume as chargeable consideration, even though no cash actually changes hands (Finance Act 2003 Schedule 4 paragraph 8). That is the one place an “adding to the deeds” transaction can quietly create an SDLT bill.
Two further wrinkles can flip the outcome: are you married or in a civil partnership at the effective date, and does the person you are adding already own another residential property anywhere in the world. Those answers decide which of the three scenarios below applies to you.
Three common scenarios (worked)
Same property in all three: a £350,000 home with a £200,000 outstanding mortgage. The change is who you are adding and whether you are married.
Scenario A: Husband adds wife (already married)
No mortgage assumption charge despite the £200k mortgage
Wife is added to a 50% share of the deeds. She is added to the mortgage too, taking on £100,000 of joint liability. Normally that £100k would be chargeable consideration, but s.73 Finance Act 2003 exempts transfers between spouses entirely.
Scenario B: Pure gift, unmortgaged property
Owner adds adult son to a mortgage-free £350k home
Father adds son to a 50% share of the deeds. No mortgage exists, no cash is paid, and the spouse exemption does not apply (it is parent and child). But because nothing of value passes in consideration, there is no chargeable consideration to tax.
Scenario C: Adding unmarried partner with mortgage
Owner adds unmarried partner to a 50% share, joint mortgage £200k
Unmarried partner is added to the deeds and to the mortgage. They take on £100,000 of mortgage liability. No s.73 spouse exemption applies. The £100,000 of assumed liability is chargeable consideration. Standard residential SDLT rates apply.
If the unmarried partner already owns another residential property anywhere in the world, the 5% additional dwelling surcharge applies to the full £100,000, giving an SDLT bill of £5,000.
Who you are adding changes the tax
The relationship between you and the person being added to the deeds is one of two factors that decide whether SDLT applies (the other is whether a mortgage is involved). The differences are significant enough to be worth seeing side-by-side.
| Who you are adding | SDLT exempt? | What about the mortgage? |
|---|---|---|
| Spouse (legally married) | Yes, s.73 FA 2003 | Their share of the mortgage assumed is not chargeable |
| Civil partner | Yes, s.73 FA 2003 | Their share of the mortgage assumed is not chargeable |
| Unmarried partner | No exemption | Mortgage share assumed is chargeable consideration |
| Adult child | No exemption | Mortgage share assumed is chargeable; ADS likely if they own their own home |
| Parent or sibling | No exemption | Mortgage share assumed is chargeable; ADS likely |
| Friend / business partner | No exemption | Mortgage share assumed is chargeable; ADS very likely |
The spouse and civil-partner exemption is the most powerful planning lever here. Transferring property to children has its own dedicated guide because the SDLT, capital gains, and inheritance-tax overlap is more involved than a simple deed addition.
Deed of trust / declaration of trust
A declaration of trust (sometimes called a deed of trust) is a separate legal document from a TR1 transfer. It records how the beneficial interest in a property is split between owners, for example, 70/30 even though both names are on the Land Registry title as legal owners.
A declaration of trust on its own does not trigger SDLT, because no legal title is being transferred. The Land Registry record stays the same; the deed only documents an agreement between the existing legal owners about how proceeds and equity are shared. SDLT applies to transfers of a chargeable interest in land, which a declaration of trust between existing owners is not.
Where a declaration of trust does become SDLT-relevant is when it accompanies a transfer of legal title, for example, adding someone to the Land Registry deeds (a TR1) and simultaneously declaring the new split (a TR1 plus a declaration). In that case the SDLT analysis follows the TR1 transfer, not the declaration. The declaration is a useful piece of paper for what happens later (sale, inheritance, divorce), but it is not the taxable event.
Common confusion
“Deed of trust” is sometimes used loosely to mean any deed that changes ownership. For SDLT purposes the right question is: is legal title being transferred at the Land Registry? If yes, it is a deed of transfer (TR1) and the SDLT rules in this guide apply. If no, it is a declaration of trust between existing owners and no SDLT is in scope.
Joint tenancy vs tenants in common
When you add someone to the deeds you must choose how the two of you hold the property. There are two options under English law: joint tenancy and tenants in common. The choice has major implications for inheritance, but for SDLT the only thing that matters is the percentage of beneficial interest being transferred.
Joint tenancy
- Both owners hold the property equally (50/50)
- On death, the survivor inherits automatically (right of survivorship)
- Cannot leave your share in a will
- Most common between married couples
- SDLT consideration on addition: 50% of any chargeable element
Tenants in common
- Owners hold defined, potentially unequal shares (e.g. 70/30)
- Each owner's share passes under their own will
- More flexibility for inheritance and tax planning
- Common between unmarried couples, business partners, or where contributions differ
- SDLT consideration on addition: their % × chargeable element
Under joint tenancy the new owner is automatically transferred 50% of the beneficial interest. Under tenants in common with a 30/70 split, the new owner takes 30%. SDLT (if any) scales with that percentage, but the structural choice does not itself create or remove an SDLT liability.
Timing around marriage and civil partnership
Transfers between spouses or civil partners are exempt from SDLT under section 73 Finance Act 2003. The exemption applies provided you are married or in a civil partnership at the effective date of the transfer (normally completion). Timing therefore controls whether a five-figure SDLT bill exists at all.
Critical timing points
- Before marriage: Adding a fiancé to the deeds is not exempt. Any mortgage share they assume is chargeable consideration at standard rates.
- After marriage: Adding your spouse is fully exempt regardless of the mortgage balance: no SDLT and no SDLT return required.
- Same-day: If you complete the transfer on your wedding day, HMRC treats you as married at the effective date and the exemption applies.
- Civil partnership: Identical rules to marriage. The exemption applies from the date the civil partnership is registered.
A common mistake is adding a partner to the deeds before the wedding, triggering an SDLT bill that would have been zero a few weeks later. If you are planning to marry and want to add your partner to the deeds, it is almost always more tax-efficient to wait until after the ceremony, then instruct the conveyancing solicitor.
For the mirror-image scenario (removing a name from the deeds on separation) see the divorce property transfer guide. Our marriage and stamp duty guide covers the broader property-tax implications around getting married.
Transferring property between owners? Check the stamp duty first
Transfers between partners, family or companies have their own rules. A specialist can advise.
When SDLT actually applies
The headline of this guide is “usually no SDLT” but there are four specific situations where it does apply. Most fall outside the “adding a partner” framing and into the transfer-of-equity territory covered in detail elsewhere.
- Unmarried partner takes on mortgage liability. Their share of the outstanding mortgage is chargeable consideration. SDLT applies if that figure crosses a rate band (£125,000 nil-rate from April 2025).
- Cash payment for the equity share. Any cash paid by the person being added is chargeable consideration in full, regardless of relationship. The spouse exemption only covers gifts between spouses: a cash payment is a sale, not a gift.
- Other secured debts assumed. If the person added takes on any other debt secured against the property, the value of that debt is added to the consideration.
- Additional dwelling surcharge (ADS). If the person being added already owns another residential property anywhere in the world at the effective date, a 5% surcharge applies to the chargeable consideration even if the underlying SDLT would have been zero. This is the most commonly missed trigger.
For the mechanics of calculating chargeable consideration in detail (particularly for buyouts and cash + mortgage scenarios) the transfer of equity complete guide is the dedicated reference. This page intentionally keeps the calculation light because most readers landing here are in scenario A or B above, with a £0 outcome.
Filing requirements (even when no tax is due)
Two separate questions, often confused: do I owe SDLT? and do I need to file an SDLT return? A return can be required even when zero tax is due.
- Chargeable consideration over £40,000: SDLT1 return required within 14 days of completion, whether or not tax is due.
- Chargeable consideration £40,000 or under: No SDLT1 return required (including pure gifts with no consideration at all).
- Spouse or civil partner transfer: Where the entire consideration is exempt under s.73, no SDLT return is needed even if a mortgage is being shared.
Late filing attracts an automatic £100 penalty (under 3 months) rising to £200 plus potential tax-based penalties. Your conveyancing solicitor will normally prepare and submit the SDLT1 as part of the transaction file, but check, because adding-to-deeds work is sometimes handled by the lender's in-house team and the filing piece can fall between the cracks.
Practical steps
The typical end-to-end process for adding someone to property deeds:
- Check lender consent. If the property is mortgaged, the lender must agree. Most will, but the new person typically has to pass affordability checks.
- Instruct a conveyancing solicitor. They will prepare the TR1 transfer deed, advise on SDLT (or confirm none is due), and handle the Land Registry application.
- Confirm SDLT position. Solicitor confirms whether the spouse exemption applies, whether any mortgage assumption creates chargeable consideration, and whether ADS is in scope.
- Decide ownership structure. Joint tenancy or tenants in common, with percentage split if the latter. Consider a separate declaration of trust if unequal contributions need to be recorded.
- Sign the TR1 transfer deed. Both parties sign. Lender signs the mortgage consent deed if applicable.
- File the SDLT1 return (if required). Within 14 days of completion. Pay any tax due at the same time.
- Register at Land Registry. Submit the TR1, SDLT5 certificate (if a return was filed), and supporting forms. The title register is updated to show the new owner.
When to use the transfer of equity guide instead
The wider transfer of equity complete guide covers scenarios where the “adding a partner” framing breaks down. Reach for that guide if your scenario involves any of the following:
- Buying out an ex-partner's share (cash plus mortgage assumed in exchange for a defined equity share)
- Substantial cash payment between parties as part of the transfer
- Commercial-style equity restructuring between business partners or family company shareholders
- Partial transfers where the existing owner's remaining share is also being recalculated
- Complex consideration involving release from indemnities, novation of guarantees, or other non-cash value
If you reached this page searching for “transfer of equity” with a buyout in mind, the transfer of equity calculator handles the chargeable consideration maths directly. The page you are on is intentionally light on calculation depth because the headline answer for “adding a name to house deeds” is usually £0.
Frequently asked questions
Do you pay stamp duty when adding a partner to the deeds?
Usually no. If you are adding a spouse or civil partner, the transfer is exempt regardless of any mortgage. If you are adding an unmarried partner and the property is mortgage-free, no SDLT applies because there is no chargeable consideration. SDLT only kicks in when an unmarried partner assumes a share of an outstanding mortgage (or pays cash for an equity share), and even then it is often £0 because the chargeable amount falls within the £125,000 nil-rate band.
How much does it cost to add a name to house deeds in the UK?
Excluding any SDLT, expect roughly £400 to £1,100 total: solicitor fees of £300 to £700 plus VAT, Land Registry fees of £20 to £95 (sliding scale based on property value), and a lender consent fee of £0 to £300 depending on the mortgage provider. The SDLT itself is usually £0. See the three scenarios above for when it is not.
Does a declaration of trust trigger stamp duty?
No, not on its own. A declaration of trust records how beneficial interest is shared between existing legal owners. No transfer of legal title to the Land Registry happens, so there is no chargeable transfer for SDLT purposes. If the declaration is filed alongside a TR1 that adds someone to the legal title, the SDLT analysis follows the TR1 transfer, not the declaration.
Is adding a wife to the mortgage subject to stamp duty?
No. Transfers between spouses are exempt from SDLT under section 73 Finance Act 2003. The wife's share of mortgage liability assumed would normally be chargeable consideration, but the spouse exemption removes that charge entirely. No SDLT return is required either, provided the spouse exemption covers the whole consideration.
What if I add my partner before we get married?
Standard SDLT rules apply because the s.73 spouse exemption requires you to be married (or in a civil partnership) at the effective date of the transfer. Any mortgage share your partner assumes is chargeable consideration. To avoid SDLT, complete the deed transfer on or after the wedding day. If timing constraints make pre-marriage transfer unavoidable, the SDLT bill is usually still modest because the chargeable amount tends to fall in the £0 or 2% bands.
Does the 5% additional dwelling surcharge apply when adding someone?
Yes, if the person being added already owns another residential property anywhere in the world at the effective date. The 5% surcharge applies to the chargeable consideration even where the underlying SDLT would be zero. So in Scenario C above (£100k consideration), if the partner being added owns another flat, the surcharge produces an SDLT bill of £5,000 (5% of £100,000). Replacement-main-residence relief and refund rules may still apply if they sell the other property within 36 months.
Does first-time buyer relief apply?
No. First-time buyer relief is only available on a purchase of a property by someone who has never owned residential property before. Adding a name to existing deeds is not a purchase in the FTB-relief sense, so no FTB relief is available, even if the person being added has never owned property.
Reviewed by
Emma 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 Calculate My Stamp Duty UK to help buyers understand the complex world of property transaction taxes.