Why BTL remortgaging matters more than ever in 2026
The buy-to-let mortgage landscape has changed dramatically over the past decade. Section 24 tax changes, PRA portfolio landlord rules, and a period of rapidly rising interest rates have made it more important than ever for landlords to be on the most competitive mortgage deal possible.
Landlords sitting on their lender's Standard Variable Rate in 2026 are typically paying 7%–8.5% interest. On an interest-only BTL mortgage of £250,000, that equates to £1,458–£1,771 per month. A competitive 5-year fix at around 4.5% brings that down to approximately £938 per month — a saving of over £500–£800 per month on a single property.
For a landlord with multiple properties, the aggregate saving from a thorough remortgage review can easily exceed £5,000–£10,000 per year. Getting the timing and lender selection right is critical.
How BTL stress testing works in 2026
BTL stress testing is the single most important criterion that determines whether you can get a specific BTL mortgage deal. It works differently from residential mortgages — instead of assessing your personal income, lenders assess whether the rental income from the property is sufficient to cover the mortgage payments at a notional stress rate.
The standard stress test requires monthly rental income to cover at least 125% of the monthly mortgage interest calculated at a notional rate of 5.5% per annum. For a limited company BTL or higher-rate taxpayer, some lenders apply a higher coverage ratio of 140% or 145%.
Stress test example
On a £200,000 interest-only BTL mortgage, the monthly interest at 5.5% is £917. At 125% coverage, you need at least £1,146 per month in rent. At 145% coverage, you need £1,329 per month.
Lenders vary significantly in the stress test ratios and notional rates they use. Working with a specialist broker means you are matched to the lender whose stress test criteria your property passes — rather than applying to multiple lenders and accumulating hard credit searches.
Limited company vs personal BTL remortgage: which is right?
The decision between remortgaging in a personal name or a limited company Special Purpose Vehicle (SPV) is one of the most significant choices a landlord can make. Following Section 24 changes — which restrict personal landlords from offsetting mortgage interest against rental income — many higher-rate taxpayers find the limited company route more tax efficient.
However, the decision is not straightforward. Limited company BTL mortgage rates are typically slightly higher than personal rates, and the number of lenders offering limited company BTL is smaller. There are also setup costs for a new SPV, and any transfer of existing personally-held properties into a company triggers stamp duty and potentially capital gains tax.
For landlords remortgaging existing properties held personally, the most common approach is to continue in the personal name and only use a limited company structure for new acquisitions. We work with tax advisers who can model the numbers for your specific circumstances.
When to remortgage and how to time your ERC
An Early Repayment Charge (ERC) is a fee charged by your lender if you repay or switch your mortgage before your fixed-rate period ends. ERCs on BTL mortgages are typically 1%–5% of the outstanding balance, tapering down as you approach the end of the fixed term.
In most cases, it makes sense to wait until your ERC period has expired before remortgaging — the savings from a better rate need to outweigh the ERC cost. However, if rates are expected to rise significantly, or if your current rate is particularly uncompetitive, we calculate whether an early switch makes financial sense.
Most lenders allow you to lock in a new rate up to 6 months before your current deal expires, which means you can start the remortgage process well in advance without paying any ERC. We recommend beginning the search process 4–6 months before your deal ends.
Documents to prepare for your BTL remortgage
Having the following ready speeds up the process significantly:
- Last 3 months' bank statements (business account if limited company)
- Current tenancy agreement for each property being remortgaged
- Evidence of rental income (bank statements showing rent credits)
- Your most recent mortgage statement for each property
- Proof of ID (passport or driving licence)
- Proof of address (utility bill or bank letter, dated within 3 months)
- For limited company: certificate of incorporation and latest accounts
- For portfolio landlords: schedule of all properties, mortgages, and rental incomes