Section 24 is the rule that stopped landlords deducting mortgage interest.
It's why profitable properties still lose money.
This shows you exactly what it costs you.
YOU ENTER
• Your other income — salary, pension, anything else
• Rental income
• Allowable expenses, EXCLUDING mortgage interest
• Mortgage and finance interest
IT WORKS OUT
• Your taxable rental profit
• The income tax you actually pay under Section 24
• The finance-cost tax credit you get back
• What the tax WOULD have been with full interest deduction
• The extra tax Section 24 costs you — the number that matters
• Your net rental income after tax
• Your effective tax rate on real profit
Every tax assumption is editable: personal allowance, band thresholds, all
three rates, the allowance taper and the finance-cost relief rate. So when
the property income rates change in April 2027, you type in the new numbers
rather than buying a new spreadsheet.
Be warned: for a higher-rate taxpayer, this often shows a profitable
property producing a loss after tax. That's not a bug. That's Section 24.
Excel (.xlsx). Works in Microsoft Excel and Google Sheets. Instant download.
Educational tool only. Not tax advice — speak to an accountant before
restructuring anything. Correct as of July 2026.
Section 24 is the rule that stopped landlords deducting mortgage interest.
It's why profitable properties still lose money.
This shows you exactly what it costs you.
YOU ENTER
• Your other income — salary, pension, anything else
• Rental income
• Allowable expenses, EXCLUDING mortgage interest
• Mortgage and finance interest
IT WORKS OUT
• Your taxable rental profit
• The income tax you actually pay under Section 24
• The finance-cost tax credit you get back
• What the tax WOULD have been with full interest deduction
• The extra tax Section 24 costs you — the number that matters
• Your net rental income after tax
• Your effective tax rate on real profit
Every tax assumption is editable: personal allowance, band thresholds, all
three rates, the allowance taper and the finance-cost relief rate. So when
the property income rates change in April 2027, you type in the new numbers
rather than buying a new spreadsheet.
Be warned: for a higher-rate taxpayer, this often shows a profitable
property producing a loss after tax. That's not a bug. That's Section 24.
Excel (.xlsx). Works in Microsoft Excel and Google Sheets. Instant download.
Educational tool only. Not tax advice — speak to an accountant before
restructuring anything. Correct as of July 2026.
