As initially reported in The Guardian, the watchdog received the complaint from rival bank Santander about the advert.
The advert, which stars Dominic West as a smoothie-drinking and large expense-filing banker, shows West encouraging the bank to close branches in order to cut costs.
When questioned about the decision as Nationwide aren’t closing branches, West’s character says: “We’re not Nationwide, are we? We’re nothing like them.”
He then goes on to tease a customer he met when he went into one of the unnamed bank’s branches.
“‘I’d like to speak to the manager. I think I’ve lost my life savings’ – total yawn fest,” he says.
When asked by his colleague what happens if a customer has lost his life savings, West’s character says “that’s what chatbots are for”.
The Nationwide advert concludes by saying that, unlike other big banks, it was not closing down its branches.
Several high street lenders have announced that they are closing down branches, with Barclays confirming at the end of January that 40 branches were flagged for closure.
Lloyds Bank, Halifax, Bank of Scotland and Virgin Money also closed several branches in the tail end of last year.
A spokesperson from ASA confirmed that it had received a complaint about a Nationwide advert but didn’t confirm who the complaint was from.
They said: “The complainant argues that the ad is misleading around other banks closing branches, and discredits and denigrates its competitors. We’re currently investigating this case and, as such, can’t comment any further at this time.”
A Nationwide spokesperson said: “We are aware of the complaint made to the ASA and await the outcome. Unlike the big banks, Nationwide has not pursued a significant branch closure programme. Since 2013, those banks have closed more than half of their branches. By contrast, we continue to believe face-to-face banking matters.
“We now have more branches than any other brand and will soon be the last one standing in almost 100 communities. Our Branch Promise means that, everywhere we have a branch, we’ll still be there until at least 2026.”
Santander declined to comment.