UK Finance has published its annual ranking of largest mortgage lenders for the residential and buy-to-let mortgage markets.
The figures show that total gross lending hit £282.1bn in 2025, up 20.1% from £234.8bn in 2024. However, total balances outstanding grew only 3.3% (£1,609.5bn to £1,662.7bn) showing that new lending is running far ahead of book growth.
Santander was the standout gross lending gainer among the major lenders, up by 57.6% (£15.8bn to £24.9bn), ahead of Barclays (+41.6%), NatWest (30%), HSBC (27.3%) and Nationwide (18.2%). Lloyds grew slowest of the big six (11.1%) but still comfortably holds the number one spot on both gross lending and market share.
Barclays overtook Santander in balances outstanding — the two are now tied for 4th place at £167.1bn each, having swapped rank order from 2024.
Among the notable fallers, Metro Bank's balances dropped 33.3% (£7.2bn to £4.8bn, rank 19 to 27), while Pepper Money fell 55.6% (£1.8bn to £0.8bn).
For the specialist/challenger lenders, Topaz Finance grew by 26.1% (rank 15 to 13), Pure Retirement by 22.4% (27 to 21) and MPowered Mortgages by 33.3% (50 to 43).
In the buy-to-let market, gross lending grew even faster than the wider market - up 22.6% (£32.8bn to £40.2bn).
Santander's gross buy-to-let lending nearly tripled — up 196.5% (£0.57bn to £1.69bn), jumping from rank 14 to rank 6. That's the single biggest percentage move in either dataset.
NatWest (65.9%) and HSBC (59.8%) also saw notable gains in buy-to-let lending.
Kensington's buy-to-let balances jumped 61.6%, climbing from rank 28 to rank 21.
Conversely, Barclays' buy-to-let balances shrank by 10.7% (£17.05bn to £15.22bn, rank 5 to 7) even as its gross lending grew — implying a large legacy back book running off faster than new business is replacing it.
Alyson Perry, head of strategic partnerships at Sesame Bankhall Group, commented: "2025 was a strong recovery year for the UK mortgage market with gross lending up 20% on the previous 12 months. However, what’s most striking is how that growth was spread across the market. Santander was the standout gainer, growing its gross lending by nearly 58%, and its buy-to-let lending nearly tripled. From our vantage point across the panel, we can see that lenders are actively vying for share, and brokers are seeing it in the form of more competitive criteria.
"The real story for advisers is further down the table - lenders like Vida Homeloans growing its balance by 29.2% and Kensington growing its buy-to-let balance by 61.6% shows real momentum building outside the big six, particularly in specialist and buy-to-let lending. That's good news for customer choice, but it also means brokers need to work harder to stay on top of a widening panel, which is exactly where a strong network or mortgage club relationship earns its value."
Richard Pike, sales and marketing director at Phoebus Software, said: “Gross lending is up over 20% but balances outstanding grew just 3.3%, which points to a lot of churn through redemptions and remortgaging. That's not an operational environment where you can afford to use legacy servicing systems - it's one where lenders need to process new completions and a wave of redemptions and product transfers accurately, and without dropping the ball on customer experience.
"Santander nearly tripling its buy-to-let lending while Barclays' buy-to-let book shrinks by over 10% whilst overall assets grew to record levels shows how differently major lenders are managing growth versus product diversification and back-book runoff right now. All are legitimate strategies and require robust servicing software to ensure a smooth customer experience.
"Overall, the figures reflect what we see from our client base who are primarily specialist lenders. Our investment in automating specialist servicing to keep operational costs down and allow clients to deal with cases by exception is more relevant than ever, especially in such an uncertain market for the foreseeable future”.
