Is your bank changing your sort code? Find out what it means for you

Almost one million banking customers are being contacted to have their sort codes and account numbers changed asthe UK's biggest banks begin the process of 'ring-fencing' their accounts.

The process is taking place between now and the 1 January 2019, as some banks separate their retail banking services from the riskier and more complex parts of their business.

This is a significant change, and the Financial Conduct Authority - the UK's financial watchdog - has published the following tips to help customers remain vigilant around the communications they receive about their accounts:

• Beware of cold-callers claiming to be from your bank. If you're unsure about the legitimacy of the call, it's best to call your bank back using the phone number on your card or bank statement.
• Bank staff will not call or email you asking for personal information, account details or the PIN for your bank or credit card.

Find out more:how to spot a scam - our tips to help you stay safe

What is ring-fencing?

The ring-fencing process involves the major UK banks separating their retail banking arm from other areas of their business, such as global trading and investment banking.

This reduces the possibility of essential banking services beingaffected by failures in these other areas, as they were in some cases during the global financial crisis of 2008.

Find out more:best banks for dealing with fraud - see which banks are rated highly by customers

Who will be affected?

Ring-fencing rules only apply to banks with more than £25bn of deposits, though this is an average over three years.

The FCA has not officially disclosed which banks would be taking part 'for legal reasons', although it's highly likely that all four major UK banks - Barclays, Lloyds Banking Group, RBS/NatWest and HSBC - will be among them.

Santander has stated that its customers will not be issued with new account numbers or sort codes, but states on its website that 'if you bank with another of the larger UK banks, the details of any accounts you have with them may change.

It says banks have worked togetherto 'make sure any Direct Debits, standing orders or bill payments will automatically be redirected'.

Your bank will tell you if your account details are changing, when thiswill take place and if there is anything you need to do.

What do you need to do?

Barclays and HSBC are among the banks to have already confirmed that customers' direct debits and standing orders will automatically be updated.

HSBC stated that the bank 'is committed to making this process as straightforward as possible for the small proportion of customers impacted.

'For most of our personal and business customers impacted, the process is automated and we will automatically update any regular payments like standing orders and direct debits.