Helping Children Buy Property: Stamp Duty for Parents

Your Options for Helping Children Buy

Parents have several ways to help a child onto the property ladder, each with very different stamp duty consequences. The method you choose will determine whether you preserve your child's first-time buyer relief, whether the additional dwelling surcharge applies, and what the total SDLT bill looks like.

Many parents instinctively want to go on the mortgage or the deeds to feel financially involved and protected. This is understandable, but from a stamp duty perspective it is usually the most expensive choice. Each of the five approaches below carries different legal, financial, and tax implications. Understanding them before committing to a method can save tens of thousands of pounds.

Joint Ownership: The Stamp Duty Trap

Joint ownership, where the parent is named on the title deeds alongside the child, is the most expensive approach from a stamp duty perspective. Two problems arise simultaneously:

These two problems compound each other: you lose the saving from FTB relief (up to £2,500) while simultaneously adding the surcharge. Our first-time buyer calculator shows what the child would pay buying alone.

A third, less obvious consequence of joint ownership is the impact on the parent's own stamp duty position. If the parent already owns a home and goes on the deeds of the child's property, they now own two residential properties. Any future purchase by the parent would be treated as a third property and attract the surcharge, unless the replacement main residence rules apply.

It is also worth noting that even a nominal share, 1% or even a fraction, is sufficient to trigger the surcharge. Some parents consider going on the deeds with a very small percentage to limit their "exposure". HMRC applies the surcharge based on whether you own any interest in a residential property, not on the size of the share. There is no minimum threshold.

Gifted Deposit: The Safest Approach

A gifted deposit is the simplest and most tax-efficient way to help a child buy. The parent gives money (not property) to the child, the child uses it as a deposit, and the child purchases the property in their sole name. The parent has no ownership stake and no legal interest in the property.

The stamp duty consequences:

• No SDLT consequence for the parent
• Child retains first-time buyer status (if eligible)
• No additional dwelling surcharge
• Child pays standard FTB rates only

From an inheritance tax (IHT) perspective, a gifted deposit falls within HMRC's seven-year gifting rule: if the parent giving the deposit survives seven years from the date of the gift, it falls outside their estate for IHT purposes. Gifts below the annual allowance (£3,000 per year) are immediately outside the estate. Larger deposits will gradually taper out of the estate over seven years. This is a separate consideration from stamp duty but worth noting as part of overall family planning.

Unlike some other approaches, a gifted deposit also means the parent retains no legal or equitable interest in the property. There is no mechanism to recover the money if the child sells or remortgages, unless a separate loan agreement is in place (which would affect the FTB mortgage status). Parents should consider this carefully if the gift represents a significant portion of their assets.

Guarantor Mortgage: Staying Off the Title

In a guarantor mortgage, the parent is named on the mortgage (guaranteeing repayments if the child defaults) but is not named on the title deeds. The child is the sole legal owner.

For SDLT purposes, ownership is determined by who holds legal title, not who is on the mortgage. Since the parent has no legal ownership, their existing properties are not counted for surcharge purposes. The child's FTB status is also unaffected.

The limitation is that traditional guarantor mortgages can still affect the parent's debt-to-income ratio for their own future borrowing, and the parent takes on legal liability for the mortgage payments. For a cleaner separation of liability, JBSP mortgages (below) are preferable.

Joint Borrower Sole Proprietor (JBSP) Mortgages

A Joint Borrower Sole Proprietor (JBSP) mortgage is a specific mortgage product offered by several UK lenders. It allows a parent and child to be joint borrowers on the mortgage (improving affordability) while the child is the sole proprietor (sole owner) on the title deeds.

The SDLT position is identical to a guarantor mortgage: since the parent has no legal ownership, no surcharge applies and the child's FTB status is preserved. JBSP mortgages are generally preferred over traditional guarantor mortgages because:

• The child's income plus the parent's income determine the borrowing amount
• Some lenders allow the parent to be removed from the mortgage after a period
• No surcharge, no loss of FTB relief

Not all lenders offer JBSP mortgages. Check with a mortgage broker who specialises in family-assisted purchases.

One consideration with JBSP mortgages is their impact on the parent's own mortgage capacity. Being on the JBSP mortgage as a borrower means the debt appears on the parent's credit profile, which can reduce their ability to borrow for other purposes. If the parent still has their own residential mortgage, lenders assessing the parent's affordability will typically factor in the JBSP commitment. Some JBSP products allow the parent to be removed from the mortgage once the child can demonstrate sufficient income to service the loan independently, typically after two to five years.

Trust Arrangements and Stamp Duty

A more sophisticated (and relatively rare) approach involves holding the property in a trust structure, with the child as the sole beneficiary. In this arrangement, SDLT is assessed against the beneficiary's (the child's) position, not the trustees'. If the child is a first-time buyer, FTB relief can potentially be preserved.

Trust arrangements also avoid the additional dwelling surcharge, as the relevant ownership for surcharge purposes is the beneficial owner (the child), not the legal owner (the trustees).

Worked Example: The True Cost of Joint Ownership

The following comparison uses a £350,000 property purchase where the parent owns a family home:

At higher property prices, this difference grows substantially. On a £500,000 purchase in London, joint ownership could cost over £35,000 more in stamp duty than a child buying alone with a gifted deposit.

These numbers illustrate why the conversation about how to help matters as much as how much to help. A parent who puts £50,000 on deposit to their child and stays off the deeds generates £0 in extra stamp duty. A parent who puts the same £50,000 in and also goes on the deeds generates £22,500 in extra SDLT, effectively consuming nearly half the gifted amount in unnecessary tax.

For personalised figures based on the property your child is buying, use our first-time buyer calculator (child buying alone) and our second home calculator (joint purchase with surcharge) to see the exact difference for your situation.