Barclays customers will be locked out of online and telephone banking once a month during upcoming five-month maintenance work.

The 'system outages' will usually start late on a Saturday and last till Sunday afternoon, and customers will be told the exact dates in the week before the work.

The first will take place this weekend between 11.30pm on Saturday and 3.30pm on Sunday. They will happen monthly (excluding December) until the end of January, but Barclays is yet to announce the remaining dates.

Barclays says the work is "to align with new banking legislation" – to get ready for new ring-fencing rules coming into effect at the start of 2019, meaning it must separate its retail banking arm from investment banking and global trading, to reduce the possibility of personal banking and savings deposits being affected by failures in other areas.

What will happen during the outages?

During this time, you won't be able to:

  • Manage your account – including checking your balance and moving money on the app or over the phone
  • Use the Pingit app (this is separate to the banking app)
  • Receive money – instead any cash will arrive in your account after the outage

Direct debits and standing orders will go through as normal, the bank says.

You'll still be able to use your credit and debit cards as usual.

Be extra careful during this period

Barclays is warning customers to be extra vigilant about online banking fraud and scams during this period.

A spokesperson said: "If you receive any communications that are unexpected and that you think might be fraudulent, please follow the usual steps to report them."