The Paper Trail of Family Lending: Fairness, Repayment and the Tax Consequences

The Bank of Mum and Dad has become a familiar feature of the UK housing market, but familiarity has not made it simple. A parent who advances a deposit, helps with a first home or supports a child through a career change may regard the money as a loan. HMRC, a divorcing spouse, an insolvency practitioner or a bereaved sibling may see something different if there is no written evidence. The central point is that lending to family is not automatically simpler than gifting. It merely shifts the complexity from one set of rules to another.

Why informal family loans drift into gifts

When money moves without terms, intentions are remembered differently. The parent may recall a conversation about repayment; the child may recall a gift. If there is no schedule, no interest, no repayment date and no request for repayment, the arrangement may look like a gift. That matters for inheritance tax. A genuine loan leaves a debt owed to the lender, which is generally an asset of the lender’s estate. A gift reduces the estate immediately and may be a potentially exempt transfer. If a loan is later forgiven, the forgiveness is generally a transfer of value and needs advice. The danger is not that families set out to mislead; it is that ambiguity invites argument.

What a written loan agreement should record

A short, properly drafted agreement is usually better than a long, vague one. It should identify the lender and borrower, the amount, the date, the purpose, the repayment terms, the interest rate, any security, events of default, and what happens on death, divorce or insolvency. It should be signed before funds are transferred. For larger sums, a solicitor should prepare or review it. The agreement need not be adversarial. It is a record of a decision that both sides understood.

Interest, repayments and fairness

Interest-free loans are common, but nil interest is a choice that should be recorded. If interest is charged, the rate and its tax treatment should be understood. Repayment may be on demand, by instalments or on the sale of a property. A loan described only as repayable “when you can” is not a useful term; it creates uncertainty and invites disagreement.

Fairness between children is often the harder issue. If one child receives a loan and another does not, parents should consider whether the will balances the position, whether the loan is to be treated as an advance against inheritance, and how that will be explained. A paper trail does not guarantee fairness, but it makes the intended treatment visible.

Security, divorce and insolvency

A loan secured by a legal charge over property gives the lender stronger rights, but it also adds complexity and cost. Unsecured loans may be lost if the borrower divorces or becomes insolvent. In divorce, a court may examine loans between family members with suspicion, particularly if the terms are vague or repayments have never been made. In insolvency, a trustee may challenge repayments or treat the loan as a recoverable asset. Security and clear terms are not a substitute for advice, but they reduce the scope for dispute.

Inheritance tax and capital gains tax interactions

For inheritance tax, the key distinction is between a loan that remains repayable and a gift that does not. An outstanding loan is generally an asset of the lender’s estate; a gift is not. The treatment of interest-free loans, forgiven debts and loans linked to property can be subtle. Capital gains tax is less often engaged by a simple cash loan, but assigning a debt, taking a share of property or varying loan rights can create disposals or complicate the borrower’s base cost. Record-keeping matters for both taxes. Parents should keep statements, repayments and any variations.

A practical 2026 checklist

• Put the agreement in writing before the money moves.
• Record the purpose and amount, and whether the loan is to be repaid.
• State the interest rate, even if it is nil, and the repayment schedule.
• Decide whether the loan is repayable on demand, on sale or by instalments.
• Consider security for larger loans and take legal advice on any charge.
• Address death, divorce and insolvency in the agreement.
• Tell the family, or at least the relevant siblings, that a loan exists.
• Review the will and any letter of wishes so the loan is not accidentally duplicated or forgiven.
• Keep a single file of statements and correspondence.
• Take tax advice before forgiving a loan or varying its terms.

Protecting the relationship and the legacy

A paper trail is sometimes presented as a sign of distrust. In practice, it is often the opposite. It protects the borrower from later claims that the money was a gift, and it protects the lender from having to rely on memory. It also gives siblings a clearer basis for understanding why one child received support and another did not. Families can choose to be generous, but they should not leave the terms of that generosity to be guessed at after a death. The loan that is written down is less likely to become the inheritance dispute that nobody intended.