If you’re a parent thinking about helping your adult child onto the property ladder, or a grandparent wondering whether to gift some of your estate now rather than leave it all to probate, you are not alone — and you are navigating one of the most consequential financial decisions your family will ever make. Get it right, and you accelerate your children’s financial security by a decade or more. Get it wrong, and you risk tax bills nobody budgeted for, fractured sibling relationships, and legal disputes that can drag through the courts for years.
The sums involved are enormous. The Institute for Fiscal Studies estimates that UK inheritances and lifetime gifts will total around £90 billion a year by the mid-2030s, with the bulk flowing from Baby Boomers to Millennials and Gen Z. Rising property prices, frozen income-tax thresholds, and the upcoming changes to agricultural and business property relief from April 2026 all make planning more urgent — not less — in 2025.
Gift or Loan? The Distinction That Changes Everything
When a parent hands over £50,000 towards a deposit, the single most important question is deceptively simple: is this a gift or a loan? The answer affects inheritance tax, mortgage affordability calculations, Capital Gains Tax, and — if the child’s relationship breaks down — how a family court divides assets on divorce.
Mortgage lenders will ask. They require a signed “gifted deposit” letter confirming the money is a true gift with no expectation of repayment. If it is actually a loan, declaring it as a gift is mortgage fraud — a criminal offence. Yet many families fudge this because they haven’t had an honest conversation about expectations.
If the money genuinely is a loan, the lender must factor the repayments into the child’s affordability assessment, which may reduce the amount they can borrow. That is an uncomfortable trade-off, but the alternative — lying on a mortgage application — is far worse.
Inheritance Tax: The Seven-Year Clock and the Traps Around It
Outright gifts between individuals are “potentially exempt transfers” (PETs). Survive seven years and the gift drops out of your estate entirely. Die within seven years and it’s clawed back into the IHT calculation, with taper relief reducing the tax only in years four to seven. So far, most people know this.
What catches families out is the gift with reservation of benefit rule. If you give your house to your children but continue living in it rent-free, HMRC treats it as still part of your estate — the seven-year clock never starts. The same logic applies to money given for a property you then use as a holiday home. These rules have real teeth, and HMRC actively investigates them.
Don’t overlook the annual exemptions either: £3,000 per tax year (and you can carry forward one unused year), £5,000 to a child on marriage, and gifts out of normal expenditure from surplus income — which has no upper limit but must be regular and genuinely affordable. Documenting these properly is the difference between a clean estate and a contested one.
Co-Ownership With Adult Children: Where Most Families Go Wrong
Some parents go beyond gifting a deposit and actually buy property jointly with a child. This can work, but the legal and financial complexities multiply dramatically.
Joint and several liability. If you are a co-borrower on the mortgage, the lender can pursue you for 100 per cent of the debt — not just your “share.” If your child stops paying, you pay everything or your credit is destroyed.
SDLT surcharge. If you already own any property anywhere in the world, the 3 per cent higher rate of Stamp Duty Land Tax applies to the entire purchase price — even if your child is a first-time buyer. On a £350,000 property, that surcharge alone is £10,500. Many families only discover this days before completion.
Future borrowing capacity. Lenders stress-test you against the full outstanding mortgage balance when you apply for credit elsewhere. A parent wanting to remortgage their own home, or a child wanting to buy a second property years later, may find they simply cannot qualify.
Tenancy in common, not joint tenancy. Non-married co-owners should almost always hold as tenants in common. This allows unequal shares, lets each party leave their share to whomever they choose in their will, and avoids the survivorship rule that automatically passes the property to the other owner on death. Without this, a parent’s share could bypass their other children entirely.
Declaration of Trust. This document — ideally executed as a deed, giving a 12-year limitation period rather than six — records who contributed what, how sale proceeds are split, and whether unequal contributions are treated as loans or equity. Without it, a court will default to equal shares regardless of who actually paid. Under the Trusts of Land and Appointment of Trustees Act 1996 (TOLATA), either co-owner can apply to force a sale even if the other objects. A Declaration of Trust is your best defence against that chaos.
A Proper Co-Ownership Agreement Should Cover
- Percentage beneficial interests and how they adjust if one party pays more over time
- Right of first refusal if one party wants to sell
- A buy-sell mechanism with an agreed valuation method (independent RICS surveyor, not Zoopla)
- Exit timeline — how many months’ notice, and what happens if the buying party cannot raise finance
- Shared expense accounts for mortgage, insurance, and maintenance
- Occupancy rules — who lives there, whether subletting is permitted
- Renovation consent thresholds — no one should be committing £20,000 to a kitchen without both parties’ written agreement
Capital Gains Tax and Principal Private Residence Relief
If the property is the child’s main home but not the parent’s, only the child’s share qualifies for Principal Private Residence Relief on sale. The parent’s share is subject to CGT at 18 per cent (basic rate) or 24 per cent (higher rate) on residential property gains. With property values rising, this can produce a substantial and entirely avoidable tax bill if the ownership structure isn’t planned from the outset.
Pensions: The Overlooked Wealth Transfer Vehicle
Following the Autumn Budget 2024 announcement, unused pension funds will be brought within the IHT net from April 2027. This is a seismic change. Until now, pensions were arguably the most tax-efficient way to pass on wealth. Families who had been deliberately spending other assets and preserving pension pots need to revisit their entire strategy. If you haven’t reviewed your expression-of-wish forms with your pension provider recently, do it now — these are not binding, but they guide trustees’ decisions on who receives your funds.
What You Should Actually Do
First, have the honest conversation: gift or loan, and on what terms. Write it down. Second, if co-buying property, instruct a solicitor to prepare a Declaration of Trust as a deed, and ensure you hold as tenants in common. Third, get an independent financial adviser to model the IHT, CGT, and SDLT implications before you commit — not after. Fourth, treat fairness between siblings as a design constraint, not an afterthought; document your reasoning in a letter of wishes alongside your will. Finally, review everything when the law changes — and in 2025, the law is changing a great deal. The families who plan properly will transfer wealth efficiently and harmoniously. The rest will transfer it to solicitors and HMRC.
Disclaimer: The information provided in this article is for informational purposes only and should not be considered financial or legal advice. Property and lending laws in the United Kingdom vary and may change over time. We always recommend consulting with a qualified solicitor and mortgage broker before entering into a property purchase or financial arrangement with another party.
