In most cases, yes. If you rent the flat out while you’re living in tied accommodation, the rent you receive is normally treated as taxable UK property income and needs to be declared to HMRC, subject to allowances and deductible costs.
How rental income is taxed in practice
You don’t pay tax on the full rent automatically. You pay tax on the profit (rent received, less allowable expenses), unless you choose to use the £1,000 property allowance instead of claiming expenses.
That allowance can be useful if your expenses are low. If you have meaningful costs (agent fees, insurance, repairs, safety certificates, etc.), it’s often better to claim actual expenses rather than the allowance.
Mortgage interest: a common misunderstanding
If the flat has a repayment mortgage, the monthly payment is not fully deductible.
For individual landlords, mortgage interest doesn’t reduce your rental profit in the same way it used to. Instead, it’s broadly given as a basic-rate (20%) tax credit, which can be less valuable if you pay higher-rate tax.
Do you need to file a tax return?
HMRC’s guidance is that you generally need to tell them if your property income is over £1,000. Whether you report via Self Assessment or another method depends on the amounts involved. As a rule of thumb, Self Assessment is required if it’s more than £10,000 before expenses, or more than £2,500 after allowable expenses.
Does tied accommodation change the position?
Usually not for the income tax point. Living in tied accommodation doesn’t normally make the rental income “tax-free”. It’s still rental income from a property you own, so it’s normally taxable in the same way as any other let property.
Where the “main residence” angle can matter is later, if you sell the flat.
A quick note on Capital Gains Tax later on
If you eventually move into the flat as your main home and later sell it, you may qualify for Private Residence Relief for the period it’s genuinely your main residence (plus the final exempt period). But time spent letting it out while you live elsewhere can still create a taxable portion of any gain. Also, “lettings relief” is now very limited and typically only applies where you lived in the property at the same time as the tenant.
Sensible next steps
Before you rent it out, it’s worth doing two quick checks:
- Speak to an accountant or tax adviser so you’re clear on what you can claim, and how mortgage interest relief will work in your circumstances.
- Make sure your mortgage and insurance allow letting (many residential mortgages require consent-to-let or a buy-to-let product).

