Renting to Family Members UK 2026 — HMRC Tax Rules, Below-Market Rent, Right to Rent, and Legal Pitfalls

HMRC's uncommercial let rule — below-market rent and loss relief

The most immediate tax consequence of letting to a family member at below-market rent is the restriction on loss relief:

• The uncommercial let rule (ITA 2007 s.127): Where a property is let at below the open market rent (typically because the tenant is a family member), any loss arising from that letting cannot be set off against other UK property income or any other income. The loss is 'ring-fenced' and can only be carried forward against future profits from the same letting. This means a landlord who lets to a child at £500/month where the market rent is £1,200/month, and whose mortgage interest and repair costs exceed the £500 actual rent received, cannot use that loss to reduce the tax on their other rental properties
• Expenses limited to actual rent received: Where a property is let below market rent, HMRC's general principle is that expenses can only be deducted against actual rental income received, not against the hypothetical market rent. A landlord who receives £500/month actual rent but has £800/month of allowable expenses can only deduct £500/month — not because of a specific statutory provision but because the expenses incurred are not 'wholly and exclusively' for a commercial rental business in the usual sense
• What is 'below market rent': HMRC assesses whether the rent is below the open market rent for the property — the amount a willing tenant unconnected to the landlord would pay in the open market. For a property let to a child at a nominal rent of £1 per week, the uncommercial let rule clearly applies. Where the discount from market rent is modest (10-15%), HMRC may not challenge the commerciality of the arrangement if there is a genuine commercial reason for the discount (e.g., reduced rent in exchange for the tenant maintaining the garden or undertaking minor maintenance)
• Section 24 mortgage interest restriction: The restriction on mortgage interest deduction (the 'section 24' relief cap) applies to family lettings just as it does to commercial lettings. The landlord can claim a 20% tax credit on mortgage finance costs — but where the actual rent is below market and losses are ring-fenced, the relief on interest costs may be limited in practice to the actual rental income received
• Rent-free letting to family: Where a property is let entirely rent-free to a family member (or at a purely nominal rent), HMRC may treat this as an 'accommodation arrangement' rather than a commercial letting at all. In this case, no expenses or mortgage interest credits are available — the property is not treated as a business letting for income tax purposes

Inheritance tax — gift with reservation of benefit

The inheritance tax implications of letting to a family member depend critically on whether the letting constitutes a 'gift with reservation of benefit':

• Gift with reservation of benefit (IHTA 1984 s.102): Where a person makes a gift of property (or an interest in property) to another person but continues to receive some benefit from that property, the gift is treated as a 'gift with reservation' for IHT purposes. The property is not treated as leaving the donor's estate — it remains in the donor's estate at death (at its then market value) and is liable to IHT as if the donor still owned it
• Classic family letting scenario — parent to child: A parent who transfers a property to their adult child but continues to live in it (or derives other benefits from it) has made a gift with reservation. Less obviously: if a parent gifts a property to their child and then rents it from the child at below-market rent, HMRC may argue that the parent derives a benefit from the arrangement — though this requires careful analysis. The gift-with-reservation rules are more directly engaged where the donor (not a third-party tenant) occupies the property
• Pre-owned asset tax (POAT): For arrangements where the GWR rules do not strictly apply but the landlord-donor derives an indirect benefit from the arrangement, the pre-owned assets income tax charge (Finance Act 2004 Schedule 15) may apply — an annual income tax charge on the 'notional rent' of the property
• Seven-year rule for outright gifts: Where a parent makes an outright gift of a property to a child with no reservation of benefit, the gift is a potentially exempt transfer (PET) for IHT purposes. If the donor survives seven years from the date of the gift, the gift is fully exempt from IHT. Taper relief applies between three and seven years. The arrangement must be genuinely outright — the parent must not occupy the property or derive any benefit from it after the gift

Capital gains tax — connected persons and market value

Any sale or transfer of a property to a family member who is a 'connected person' for CGT purposes is deemed to take place at open market value, regardless of the actual consideration:

• TCGA 1992 s.18 — connected persons market value rule: A disposal to a connected person (as defined in s.286 TCGA) is treated for CGT purposes as made at open market value — even if the actual consideration is zero, below market value, or the property is inherited or gifted. This means a parent who gifts a property to a child triggers a CGT disposal as if the property was sold at market value on the date of the gift
• Who is a connected person (TCGA 1992 s.286): Connected persons include: spouses and civil partners; lineal descendants (children, grandchildren) and their spouses; siblings and their spouses; parents and grandparents; business partners. For tax purposes, a transfer between connected persons cannot be treated as a no-gain-no-loss disposal (unlike transfers between spouses/civil partners — TCGA 1992 s.58)
• Annual exempt amount: For 2025/26, the CGT annual exempt amount is £3,000. On a property with a large gain (say £150,000 gain after indexation and costs), the annual exempt amount makes minimal difference to the overall CGT liability
• Private residence relief interaction: Where the property was the landlord's main residence at some point, private residence relief (PRR) may reduce the chargeable gain — the period of actual residence plus the final 9 months of ownership is always exempt. Where the property has been let throughout, PRR does not apply
• Holdover relief: Gift holdover relief (TCGA 1992 s.260) is available for gifts of business assets and certain agricultural property but NOT for gifts of residential investment property. A landlord gifting a BTL property to a child cannot use s.260 to defer the CGT — the gain crystallises on the gift date

Legal requirements — right to rent, AST, and HMO licensing

The domestic relationship between landlord and tenant does not exempt either party from statutory compliance obligations:

• Right-to-rent checks: The right-to-rent scheme (Immigration Act 2014) requires landlords to check the immigration status of all adult occupiers before the start of a tenancy. This obligation applies equally where the tenant is a family member — a landlord who lets to an adult child or sibling must still carry out and document the right-to-rent check before the tenancy begins. Failure attracts civil penalties of up to £5,000 for a first breach and up to £10,000 for repeat breaches
• Assured shorthold tenancy or excluded licence: Where the family member has exclusive possession of the property (the landlord does not live there), the tenancy is governed by the Housing Act 1988 as an assured shorthold tenancy — the same legal regime as any other residential letting. All AST requirements apply: deposit protection, prescribed information, How to Rent guide, gas safety certificate, EPC, electrical installation condition report, and (from 1 May 2026) periodic tenancy under the Renters' Rights Act. Where the family member lives with the landlord and does not have exclusive possession of the whole property, the arrangement may be an 'excluded licence' outside the 1988 Act
• Deposit protection: If a security deposit is taken (even from a family member), it must be protected in a government-approved tenancy deposit protection scheme within 30 days of receipt and prescribed information must be served. A landlord who fails to protect a family member's deposit is exposed to the same penalties as for any other tenant — 1-3x the deposit amount
• HMO licensing: Where a property is let to two or more family members who form more than one household (for example, adult children from different relationships), mandatory HMO licensing may apply. The 'family' exception in the Housing Act 2004 definition of an HMO covers members of the same family (broadly defined) who form a single household — not multiple separate households

Frequently asked questions