Free tool for UK landlords
Add each of your buy to let properties to see how the whole portfolio looks on rental stress, interest cover, loan to value and yield, the way most lenders look at it. Fill it in and you also have your whole portfolio in one document you can keep, or hand to a broker or lender when they ask, since it captures the details they usually request. Your details stay on your own device, and you can download everything as a PDF or an Excel file.
These defaults reflect criteria a typical lender might use. They are indicative only and lenders differ, so adjust them if you know the figures that apply to you. The stress rate is the notional interest rate rent is tested against, and the interest cover ratio (ICR) is how far rent must exceed that stressed interest.
Add a property and fill in its value, mortgage balance and rent to see your portfolio summary.
A close or short result is not the end of the road. If a property only just covers, or falls a little short, you may still have options. Some lenders can take your personal income into account alongside the rent (often called top slicing), and a like for like remortgage with no extra borrowing is usually assessed more leniently than a purchase or raising extra money.
Important, not financial advice: this tool gives estimates using typical criteria. Actual lending rules, stress rates, interest cover ratios and exposure limits vary between lenders and change over time, so a real decision may differ. Always confirm the figures with a qualified mortgage broker and the lender before you rely on them.
Most lenders do not test the rent against the actual rate you pay. They usually take the mortgage balance, apply a higher stress rate, work out the notional interest, then check the rent covers it by the required interest cover ratio (ICR).
For a portfolio landlord this is usually assessed across the whole portfolio, so this tool compares your total rent against the stressed interest on your total borrowing, and shows whether it sits within, close to, or outside the levels most lenders look for.
The required ICR depends on how the property is held and what it is:
The portfolio figure blends each property's requirement, weighted by its mortgage balance, so larger loans carry more weight. You can change any of these in the assumptions if your lender uses different numbers.
Loan to value (LTV) is your borrowing as a share of the property value, shown per property and across the whole portfolio. A portfolio is usually expected to sit at or below 75% overall.
Gross yield is the annual rent as a share of the property value. It is a quick guide to how hard each property works, before costs and tax.
A rent that has sat unchanged for a long time can quietly fall behind the market. Because lenders usually assess on the lower of market rent and actual rent, that can cause a remortgage to fall short later, so the tool flags any property where the rent looks low against the mortgage.
Once you hold four or more mortgaged buy to let properties, a lender will usually run a background assessment across your whole portfolio at application, not just the property you are applying for. The tool lets you know when you reach that point.
Lenders also tend to watch geographic exposure. Holding several properties in the same postcode can limit which lenders will help, so the tool gives a quiet flag when several of your properties share an area.
Once you have a view of the portfolio, the affordability calculator helps you size a single new loan, and the profit and ROI calculator shows the real return after costs.