This number, which is prefixed by the local area code for Barnsley, is being used by scammers pretending to be calling from HSBC. This is either a phishing scam, or a call back scam where they try to get you to phone them back on a premium rate phone line. Either way it is best that you do not answer this phone call, or hang up immediately. Below is an example of this number being reported, on Twitter:
@HSBC_UK I received a scam call today, and they claimed they are Hsbc as caller ID is Hsbc number. please take a look and advise your customer to be cautious! pic.twitter.com/l8GvHJF1fc
— Liu (@Liu_Chiachen) September 23, 2020
Although the author of this tweet answered the call, fortunately she was able to identify it as a scam call. She also notified HSBC. If you receive a call from the number 01226 261010 the you can let HSBC know by emailing HSBC@phishing.co.uk