Nine credit unions went bust last year, the highest number of collapses since 2010 when 10 went into default.
It brings the total that have gone under in the past decade to 73.
Despite this, the number of credit union members has risen by 250% over the same period and more than two million people now use them.
There are hopes that the sector can provide an alternative, low-cost source of finance given the recent crackdown on high-cost payday lenders.
Credit unions are locally-based organisations, where members pool their savings to lend to one another.
Some credit unions are trying to transform themselves given the growing appetite for digital banking.
Lucie Russell is campaign director at Fair By Design, which aims to make sure that essential services do not cost more to low income consumers.
She said people are put off credit unions because they lack digital services.
“They don’t have widespread online services, it is a problem,” she says. “We need to build their infrastructure so they can be competitive and accessible for more digital customers, as well as serving those who are digitally excluded and want that local branch access.”
And while cosy, community organisations may be the image most people have of credit unions, she believes that with help they could transform into “customer-focused challenger banks”.
If a credit union goes bust, the Financial Services Compensation Scheme (FSCS) reimburses depositors up to £85,000 each.
However, not all credit unions that have closed have gone bust, some simply wind up their books. Between 2000 and 2017 – the latest year that Abcul has data for – the number of credit unions in Great Britain fell from 700 to 312.
Matt Bland, head of policy at the Association of British Credit Unions (Abcul), says: “We do unfortunately see a number of credit unions fail each year. Typically the credit unions that do fail are very small, with a few hundred or maybe a thousand people using them.
“These are not typical of the best performing credit unions in the sector and in those credit unions we are seeing significant digitalisation and professionalisation taking place.”
Despite the fall in the number of credit unions, the number of members has risen from 325,000 at the start of the century to over two million by 2018. Combined, their assets now total £3.28bn.
Credit unions are particularly important because the Financial Conduct Authority is cracking down on high-interest credit options, such as payday loans and rent-to-own firms.
Its 2018 report into alternatives to high-cost credit suggested that credit unions and other social lenders could be key in giving customers more choice.
However, the UK credit union sector remains small compared with other countries. In the US, more than half the population have used credit unions.
Phil Andrew, chief executive of StepChange Debt Charity, said: “Credit unions and community lenders are an important and valued part of the financial landscape.
“However, the capacity of the existing sector to deliver the increased volume of low-cost credit that would truly replace the high-cost credit market is limited.”