Customers will be able to use their banking apps to freeze suspicious scam transactions and get repaid within 24 hours, if their funds are recoverable, under a mandatory draft code proposed by Treasury to stop an 80 per cent blowout in scam losses.

However, consumer groups say the code relies too heavily on customers knowing they have been scammed and have called for Australia to emulate the United Kingdom and make banks statutorily liable for scams on innocent customers.