Saffron Building Society's chief executive on rebuilding mortgage origination, lending growth ambitions and why the biggest risk is doing nothing
Heritage has long been one of the strongest selling points for Britain's building societies. The chief executive of one mutual founded in 1849 believes it will count for far less in the years ahead, and that the bigger danger for his society is standing still.
Colin Field (pictured top), chief executive of Saffron Building Society, has spent 13 years at the Essex-based lender and has led it for just over a decade. On 17 September, the society announced a partnership with FintechOS to rebuild its mortgage origination platform. Saffron has more than £1.5 billion in assets and over 118,000 members, while it distributes its specialist mortgages exclusively through intermediaries for new business.
"What I'm worried about is actually how do we remain and continue to be relevant moving forward because that's the key thing," Field told Mortgage Introducer. "Having the heritage is wonderful, and yes, we are a trusted brand, and we do take that trust very, very seriously."
Saffron originated about £200 million of mortgage business five years ago and expects to write more than £350 million in 2026. Field wants that figure to reach £500 million a year, with the mortgage book on course to grow by around 12% this year.
What convinced the board to act now?
Field identified three pressures that convinced the board Saffron's operating model had to change. Customers' lives have become more complex since the pandemic, with more borrowers relying on multiple income sources, and people in every age group are now comfortable with digital channels. Competition has intensified as neobanks, non-bank lenders and clearing banks have moved into parts of the mortgage market where they did not previously operate.
The third was technology. The origination platform Saffron installed more than a decade ago could not build new propositions or reprice at the speed the market now demands, and scaling volume on it would have meant hiring more staff. The pressure to do more with fewer people is felt across the sector, as analysis of efficiency rankings among UK building societies showed.
"What the board realised was actually the risk that we faced was the risk of standing still, the risk of doing nothing at a point where everybody else is facing into those same challenges and responding in a way that suits their business as well," he said.
"It would have been lovely, given just how volatile the world is at the minute and seeing where interest rates are going, to be able to say to the board, look, I think we should sit tight for a couple of years and we'll probably be okay. But my instinct tells me that we're at one of those moments."
The programme has been kept deliberately narrow. Saffron created a new role for Qasir Aslam, the society’s chief transformation officer, and has resisted pressure to take on other projects at the same time.
"At times that doesn't make me popular with colleagues who are saying to me, well, Colin, I'd like us to be doing the savings origination system because that's not great, it's not as good as we'd like it to be, and I agree with them," he said.
How will the new mortgage origination platform change things for brokers?
In December, the Intermediary Mortgage Lenders Association (IMLA) forecast that around 87% of regulated mortgage lending would go through brokers across 2026 and 2027, making the origination experience central to winning business.
The FintechOS platform covers broker registration, decisions in principle, applications, underwriting, offers and completions. The first release, covering the owner-occupied range, is due in May 2027, alongside a new intermediary website designed for brokers who, like consumers, increasingly research lenders using AI tools rather than search engines. New functionality will then follow every two to three months while the old system is scaled down.
"We don't want to do a large piece of development which could take two years and then a big reveal into brokers," Field said. "We just think that's not what they want."
Brokers are central to the plan. Field said tougher competition has raised the bar for any lender that wants to win intermediary business.
"The ability to service brokers and customers with really good experiences and being able to give decision certainty at the right pace is really critical going forward," he said. "Otherwise, you will not be in the consideration list of a broker or customer going forward as well."
Human contact will remain where it counts, with a welcome call for every broker who registers with the society.
Finding a technology partner built for mutuals
Choosing a supplier raised a problem familiar to smaller mutuals. Field said building societies have historically had little choice of enterprise technology. Options have grown since, but some vendors offer strong products on a take-it-or-leave-it basis and focus on the larger banking clients that generate most of their revenue.
"It was really important to us that we were partnering with a business that actually would take the time to understand us, and we would be important to them," he said.
Saffron also wanted control over its own changes, rather than relying on change requests or waiting for a feature to appear on a vendor's product roadmap.
"If we want to change our proposition or change our journeys or build new products as much as possible, I would like us to be able to do that ourselves."
Where does automation end and judgement begin?
The new platform will automate more of Saffron's underwriting, and Field is blunt about what that means for one of the sector's most cherished traditions.
"I hear a lot of building societies will talk about manual underwriting. I don't think manual underwriting is an important thing at all. I think good decisioning is an important thing."
Human judgement still matters, he added, but only where a case genuinely needs it.
"Ideally what I'd like is if there's, say, eight things that an underwriter is due to look at and make a decision on. If six of them are absolutely fine, I don't really want the underwriter looking at it. I want them looking at the two things and giving them the confidence that they're the two things that they need to go and work through."
The Financial Conduct Authority has been encouraging firms to test the technology through its AI Lab and Supercharged Sandbox programmes, and Field said the regulator's engagement had given the board confidence. He remains cautious about embedding AI too deeply while its long-term cost is unclear.
"It is absolutely critical to me that we actually have this modular tech stack which is accessible to AI in the future," he said.
Keeping people at the centre of change
Field said most of his peers are changing their technology, but he is realistic about delivery.
"People will say to me, Colin, but we know that the delivery will take longer and it'll be more expensive. And I kind of flip it on its head and say, well, it's hardly likely to be cheaper and quicker, is it?"
He said success would be measured by people as much as systems.
"Success for me is that I've got colleagues who will say this has been a really exciting time, we've really liked the change and my career's developed."
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