Web design and development experts at Rouge Media examined data from the website monitoring service for 18 UK banks and building societies offering current accounts.

Researchers found Santander customers faced the most difficulty accessing their accounts and using banking services in 2021. Downdetector officially recorded 64 different problems and outages last year across Santander’s website and app.

Santander also has the highest number of all-time user complaints (6,635) on the web monitoring platform – higher than any other UK bank or building society.

In August 2021, Santander announced plans to close 111 high street branches in response to the ongoing shift by customers towards mobile and online banking, a long-term trend which has been accelerated by the pandemic. The bank had issues with its online banking in both May 2021 and November 2021.

A Santander spokesperson said: “The resilience of our services is a top priority for us and we are making constant improvements to our systems to ensure we provide the most reliable service as possible for our customers. Whenever a problem arises, we keep customers closely informed, provide alternative ways to access our products and services wherever possible and work with those impacted to ensure they are not left out of pocket as a result.”

Lloyds Bank comes in close second place in the study, with 44 problems and outages logged for its website and app last year. Overall, 3,920 user complaints had been left on Lloyd’s Downdetector profile from customers experiencing issues. In June 2021 it announced it was shutting 44 branches.

TSB was in third place in the study, with Downdetector recording 38 confirmed outages or problems with its online banking services in 2021. Its profile also has 4,120 user-generated complaints – the second highest of the 18 banks studied.

TSB disputed Rouge Media’s findings. It claims that appearing on Downdetector is different to an actual outage where customers are impacted because of a bank glitch. It said that according to Financial Conduct Authority (FCA) data, TSB is actually mid table for IT outages, finishing 12th highest for outages from September 2020 to October 2021. It said that TSB only had three outages recorded by the FCA in 2021, not 38.

Making up the rest of the top five most unreliable online banks was Halifax with 35 incidents recorded, and Barclays with 33 incidents.

The rate of bank branch closures has been accelerated by the Covid-19 pandemic and falling footfall on high streets across the UK. In response to this trend, the Financial Conduct Authority (FCA) is considering new rules to stop banks from shutting high street branches to ensure consumers and businesses can still access cash.

At the other end of the table, Starling Bank ranked as the most reliable online banking service in 2021, with Downdetector logging just one issue last year. It also has the fewest user-generated complaints left on its profile at just 38.

Other challenger banks, Monzo and Smile, are also among the most reliable as found by the study, with only three and two issues respectively reported by Downdetector in 2021.

Andy Woods, director at Rouge Media, said: “With our reliance on online banking services growing every year, it has been really interesting to analyse which customers are experiencing the most problems with their digital accounts.

“It’s clear that many major banks continue to face outages and disruptions across their digital services, and with so much competition in the market from new online-only entrants, this could cause frustrated customers to go elsewhere.”