UK property income · Cardiff landlord calculator
Rental Profit Tax Calculator
Work from your share of the rent, allowable running costs, property losses and other taxable income to estimate the profit reported and the Income Tax arising.
The calculator keeps mortgage interest outside the rental-profit deduction for an individual residential landlord, then tests the separate finance-cost tax reduction.
Annual property calculation
Calculate taxable rental profit and Income Tax
Enter totals for one tax year. If the property is jointly owned, enter the whole-property figures and your beneficial ownership percentage.
- Your share of property income
- Deduction used
- £0.00
- Profit before brought-forward losses
- £0.00
- Property loss used
- £0.00
- Taxable property profit
- £0.00
- Personal Allowance used overall
- £0.00
- Income Tax before finance-cost reduction
- £0.00
- Finance-cost tax reduction
- £0.00
- Unused finance costs indicated
- £0.00
- Estimated property balance after tax deducted
- £0.00
The calculator deducts your share of allowable non-finance costs and tests finance-cost relief separately.
Rent a Room relief, premium calculations, furnished-holiday transition adjustments, foreign income, savings, dividends, pension relief and special ownership rules need a full tax computation.
Direct answer
Rental profit is not simply rent less the mortgage payment
An individual landlord normally starts with rental receipts and deducts allowable revenue expenses. Capital improvements and mortgage capital are not rental deductions. Finance costs on residential property are dealt with through a separate tax reduction rather than deducted from rent.
If the property allowance is claimed, it replaces actual expenses for that property business and the finance-cost reducer is not claimed for that year.
Calculation order
How the rental profit tax calculation works
- 01
Apply your ownership share
Rental income and property costs are restricted to the beneficial share entered.
- 02
Choose expenses or the property allowance
Actual allowable costs can create a property loss; the property allowance cannot create a loss.
- 03
Use earlier property losses
Brought-forward losses reduce profit from the same property business before Income Tax.
- 04
Stack property income after other income
The taxable property profit uses the remaining Personal Allowance and tax bands for the selected year.
- 05
Test residential finance-cost relief
The reducer uses the lowest permitted base and cannot create an Income Tax repayment by itself.
Live tax-year reference
Property Income Tax rates used
The selected tax year controls every rate and allowance below.
Official references: working out rental income, property allowance, residential finance-cost relief and confirmed property-income rate changes.
Before filing
Figures a Cardiff landlord should reconcile
Start with the property statement, but do not assume every outgoing shown by the agent is tax-deductible. Reconcile income to bank receipts and keep invoices supporting repairs, insurance, service charges and professional costs.
Keep together
- completion statement and ownership evidence;
- annual letting-agent and rent schedules;
- repair invoices separated from improvements;
- lender’s annual interest certificate;
- property-loss and unused finance-cost brought-forward figures;
- NRL tax certificates where tax was withheld.
Common questions
Rental profit tax calculator questions
Can I deduct the whole mortgage payment?
No. Capital repayments are not deductible. An individual with residential property finance costs normally claims a tax reduction on eligible interest and finance charges, subject to statutory limits.
Should I use the £1,000 property allowance or actual expenses?
Use the method that is available and produces the correct result from your facts. The property allowance replaces actual expenses and cannot create a loss. It is not available alongside a finance-cost reducer that reduces the year’s liability.
Does joint ownership always mean a 50:50 split?
No. Beneficial ownership and the relationship between owners matter. Spouses and civil partners have specific rules and may need Form 17 with evidence where a different beneficial split is claimed.
Does this calculator cover a limited company?
No. A company normally calculates property profit under Corporation Tax rules, where financing costs and loss rules differ.
Confidential enquiry
Need the rental calculation checked?
Tell us the tax year, ownership share, annual rent and the main costs involved. Do not include a UTR, National Insurance number or bank details.