West One has raised its standard residential mortgage loan-to-income (LTI) cap from 5.0 to 5.5 times income. At the same time, Santander cut rates by up to 21 basis points. Two lender moves in one week - and together they could shift the numbers for buy-to-let (BTL) investors sitting just below the old affordability line.
What West One's higher LTI cap means in practice
The new 5.5x cap applies to purchases and remortgages across all core credit tiers, according to Mortgage Strategy (June 2026). It also extends to self-employed borrowers: the minimum trading history required drops from two years to one. That is a meaningful change for contractors and sole traders who previously could not qualify under standard criteria.
Run the numbers on what 5.5x LTI actually delivers. On a gross income of £50,000, the old cap allowed borrowing up to £250,000. The new cap allows up to £275,000 - a £25,000 increase on the same salary. For a BTL purchase at 75% loan-to-value (LTV), that extra headroom could bring a property in the £360,000 range into play where it previously was not.
West One said the move is designed to support borrowers who are underserved by mainstream lenders (Mortgage Strategy, June 2026). If the big banks have been saying no, this specialist lender has now moved its ceiling higher. You can see how the new LTI figure interacts with rental stress tests using the Property Filter stress test calculator.
Santander's rate cuts - what they cost you per month
Santander trimmed rates by up to 21 basis points (bps) across selected products, per Mortgage Strategy (June 2026). One basis point equals 0.01%, so 21bps equals a 0.21 percentage point reduction.
On a £250,000 interest-only BTL mortgage, a 21bps cut saves approximately £44 per month on the interest bill. On a repayment basis over 25 years, the monthly saving is around £26. Not a transformation, but real money - and it compounds over a full term.
The cuts position Santander more competitively in a market where lenders are actively competing for business. For investors refinancing this quarter, it is worth running a full comparison across the rate card before committing.
What to do with both pieces of news
For most BTL investors, West One's LTI change is the more structurally significant move. The self-employed relaxation in particular opens a route that was closed to sole traders and contractors with less than two years of accounts. If you are in that category and have been planning a purchase, the criteria have shifted in your favour.
For investors thinking about wider strategy, the Property Filter negotiation and finance hub covers how to work out which product type fits your portfolio. If you are still thinking through investment structure itself, the property investment strategies section is worth a read before you speak to a broker. And the free resources page has calculators and guides to help you stress test the numbers before you commit.
Key takeaways
• West One raised its residential LTI cap from 5.0x to 5.5x income as of June 2026, adding up to £25,000 in borrowing capacity on a £50,000 salary.
• The self-employed minimum trading history drops from two years to one - a significant opening for contractors and sole traders.
• Santander cut rates by up to 21bps, saving around £44 per month on a £250,000 interest-only BTL mortgage.
• Both changes apply to purchases and remortgages.
