Putting a property into joint names can be a disposal for Capital Gains Tax, a purchase for Stamp Duty Land Tax and a gift for Inheritance Tax, all in one transaction. Marriage or civil partnership removes most of the CGT and IHT cost, but it does not stop SDLT if the incoming owner takes on part of the mortgage or pays cash. What you pay depends on who the partner is, what the property is used for and whether any debt moves with the share.

What actually changes when a partner is added to the title?

The tax follows the beneficial interest, not just the names on the register. Under section 60 of the Taxation of Chargeable Gains Act 1992 (TCGA 1992), property held by a nominee or bare trustee is treated as belonging to the person beneficially entitled, so adding a partner purely as a trustee who holds the whole property for you is not a disposal.

In most cases, though, the point of the exercise is to give the partner a real share. That share should be recorded, usually in a declaration of trust, stating whether you hold as joint tenants or as tenants in common and, for tenants in common, in what proportions. The form of ownership also decides what happens on death, which is covered in joint tenants vs tenants in common. Once a beneficial share passes, three taxes need to be checked separately.

Is there Capital Gains Tax if we are married or in a civil partnership?

Usually not. Section 58 TCGA 1992 treats a disposal between spouses or civil partners who are living together as made for whatever amount gives neither a gain nor a loss. HMRC’s guidance says you do not pay CGT on assets you give or sell to your spouse or civil partner unless you separated and did not live together at all in that tax year.

The receiving spouse takes over a share of your original cost, so the gain is deferred rather than removed: it is taxed if and when the property is sold outside the marriage. This is why couples often move a share of a let property between them before a sale, to use both annual exempt amounts and basic rate bands. That planning is covered in transfers between spouses and civil partners.

What if we are not married?

A gift to an unmarried partner is a disposal at market value. Section 17 TCGA 1992 deems a disposal made otherwise than by way of a bargain at arm’s length, and in particular by way of gift, to be made for market value. So giving away half of a property is taxed as if you had sold that half for half its value, even though no money changes hands.

For your own home this rarely produces tax. Under section 223(1), no part of the gain is chargeable if the property has been your only or main residence throughout your ownership, or throughout except for the last 9 months. A share given away is covered in the same way as a sale.

A rental property is different. The gain on the share is chargeable, and if it is UK residential property you must report and pay any CGT due within 60 days of completion, as explained in the 60 day property return. For 2026 to 2027 the annual exempt amount is £3,000 and residential gains are taxed at 18% within the basic rate band and 24% above it. More detail on couples who are not married is in capital gains for unmarried couples.

When does Stamp Duty Land Tax apply to a transfer into joint names?

SDLT applies in England and Northern Ireland. Property in Scotland is subject to Land and Buildings Transaction Tax, and property in Wales to Land Transaction Tax, which have their own rules.

SDLT is charged on chargeable consideration, meaning anything of monetary value given for the share. A pure gift with no consideration is normally free of SDLT. But HMRC’s guidance is explicit that taking on liability for a mortgage counts as consideration: in its own example, a partner who takes on 50% of a £600,000 mortgage when half the property is transferred on marriage has given £300,000 of chargeable consideration. Cash paid for a share of the equity is added to the share of debt assumed.

The guidance applies this whether you marry, enter into a civil partnership or simply move in together, so there is no general SDLT exemption for spouses. It also shows that a return may still be needed where the consideration is below the threshold. For residential purchases the nil rate band runs to £125,000, followed by 2% to £250,000 and 5% to £925,000. The mortgage rules are covered in more depth in SDLT on gifts of property with a mortgage.

Do the higher rates apply?

You usually pay an extra 5% on top of the standard rates if you own another residential property after the purchase. For a married couple, HMRC’s manual at SDLTM09820 confirms that from 22 November 2017 transactions solely involving the transfer of interests between spouses or civil partners living together are disregarded for the higher rates. Unmarried partners have no such disregard, so a partner who already owns a buy to let and takes on part of the mortgage can face the surcharge. See SDLT higher rates for additional dwellings.

What are the Inheritance Tax consequences?

Gifts between spouses or civil partners are exempt. HMRC’s guidance says you can give them as much as you like during your lifetime as long as they live in the UK permanently and are legally married to you or in a civil partnership with you.

A gift of a share to an unmarried partner is a lifetime gift. No tax is due if you survive 7 years. If you die within 7 years it counts towards your estate, with taper relief reducing the tax on gifts made 3 to 7 years before death where gifts exceed the £325,000 threshold. Where the partner pays something or takes on debt, only the shortfall below market value is the gift, because HMRC treats money you lose by selling for less than something is worth as a gift.

Can I keep living in a home I have given a share of?

Normally, keeping the use of something you have given away is a gift with reservation and the asset stays in your estate. Section 102B of the Finance Act 1986 makes an exception for a gift of an undivided share of an interest in property: there is no reservation while you and the person you gave it to both live there and you receive no more than a negligible benefit from them connected with the gift. Couples sharing a home usually fall within this.

How is rental income split after the transfer?

If you live with a spouse or civil partner and receive income from property you jointly own, HMRC’s guidance says you will normally be taxed on an even split. To be taxed on unequal shares you need actual unequal beneficial interests, evidence such as a declaration or deed, and a declaration on Form 17. Unmarried owners are taxed on the profits they are receiving or entitled to under section 271 of the Income Tax (Trading and Other Income) Act 2005, as HMRC explains at PIM1030. More detail is in jointly owned rental property.

How does this work in practice?

Illustration only. Priya owns a flat worth £300,000 that has always been her only home. It has a £200,000 mortgage. She transfers a half share to her partner Tom, who takes on half the mortgage (£100,000) and pays nothing else.

  • CGT: whether or not they are married, the gain on the half share is covered by main residence relief because the flat has been Priya’s only home throughout.
  • SDLT: Tom’s chargeable consideration is £100,000, the debt he assumes. This is below £125,000, so at standard rates no SDLT is due, but a return may still be needed.
  • Higher rates: if Tom already owns a buy to let and they are not married, the 5% surcharge applies to the whole £100,000, giving £5,000. If they were married and living together, the transfer would be disregarded for the higher rates.
  • IHT: if married, the gift is exempt. If not, the gift is the £150,000 share less the £100,000 debt Tom takes on, so £50,000 is a lifetime gift that is only relevant for IHT if Priya dies within 7 years.

If the flat were a rental property and they were unmarried, Priya would also have a chargeable gain on the half share at market value and a 60 day return to file.

What mistakes come up most often?

  • Assuming marriage removes SDLT. It removes the higher rates on transfers between spouses, not the charge on mortgage debt assumed.
  • Forgetting that a share of the mortgage is consideration, even when the transfer feels like a gift.
  • Giving an unmarried partner a share of a let property without working out the market value gain or filing the 60 day return.
  • Changing the legal title without recording the beneficial shares, which leaves the CGT, income and IHT position unclear.
  • Filing Form 17 for unequal rental income without first creating genuinely unequal beneficial interests.
  • Applying SDLT rules to property in Scotland or Wales.

If HMRC opens a check into your return, tax investigation insurance pays your accountant’s fees. Solar Protect cover pays up to £100,000 with no excess; it never pays tax, interest or penalties. Read how our cover works or get a quote.

Related Accountapedia entries

Sources

Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 19 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.