Update National Australia Bank won’t say when the payment troubles afflicting its customers and clients at other banks will be resolved, hours after the problems first surfaced.

Customers of NAB and a string of other banks have said they did not receive their usual pay transfers this morning. ANZ Bank, CommBank, and Westpac customers whose employers bank with NAB have also reported problems.

A screengrab from NAB's Twitter page (http://twitter.com/#!/NAB), with apology after apology to angry customers who've vented their anger on the social networking site.

The issue for NAB comes just months after an extensive failure prevented thousands of people from receiving their funds in late 2010.

As of 11.30am, eastern Australian time, the bank was apologising to customers via Twitter, while a note on NAB’s internet banking site, said: "NAB is currently experiencing some delays, some transactions may not be appearing in customer accounts and some account balances may not be up to date."