Westpac has apologised to customers for the error.

Westpac has apologised for an error that saw an email sent to a customer that began "Hello Asian".

The email had a subject line that said, "Asian, your statements are moving online".

This was followed by the greeting, "Hello Asian".

‘Unfortunate’ is one way of putting it. Screwup of the week goes to Westpac! pic.twitter.com/n7MTrfispy — Brenda (@digitalharpy) November 17, 2016

Westpac spokesman Chris Mirams said it was a "regrettable error" and the customer affected had received an apology.

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No ethnic information was collected in the process and Westpac was confident the mistake would not happen again.