Wise has accused six of the UK’s largest banks of hiding fees in their exchange rate.

Based on new research carried out by the foreign exchange firm, it said that HSBC charges the highest of all the major High Street banks, with a 3.7 per cent "hidden mark-up".

The claims come weeks after the bank announced the launch a new payments platform called Zing, in a move that was praised by Wise.

Wise says that while the new platform is transparent about its fees, HSBC doesn't offer the same transparency to its existing customers.

HSBC declined to comment.

According to Wise, Lloyds Banking Group charges a 3.6 per cent hidden fee, while Barclays charges 2.75 per cent.

It claims that NatWest, TSB, and Santander all have a hidden mark-up of 2.5 per cent.

TSB told FStech that it outlines its FX fees on its website.

Wise said that Barclays and Lloyds bank “play-act at being transparent” through what it describes as a hard-to-find disclaimer that details the hidden fee as a mark-up.

“We recognise the importance of being transparent with the charges and fees customers may incur," said a Barclays spokesperson. “Our costs for currency transfers are visible and customer’s will have sight of the exchange rate fee and other associated Barclays charges via their choice of channel - Barclays App, online banking, branch or telephone banking."

Wise claims that the other banks don't currently have any form of disclaimer about hidden exchange rate fees.

However Santander said that customers making an international currency transaction are provided the exchange rate, and any associated fees, before making any transfer.

Wise did however say that newer banks like Starling and Monzo are completely transparent about their fees.

"Banks still hide their mark-ups and refuse to be transparent, because they believe hiding fees gets customers to overpay," said Kristo Käärmann, chief executive and co-founder, Wise. "They may be right. Not all people and business owners have the time and desire to calculate the hidden margins they are charged."

Käärmann continued: "The rise of new companies that are open about fees, including Wise, shows the value of transparency. HSBC’s launch of Zing suggests they understand this too - making their refusal to come clean to their existing customers is quite cynical. It’s time banks were transparent about exchange rates, and for hidden fees to finally become a thing of the past.”

FStech has reached out to Lloyds Banking Group and NatWest for comment.

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