ANZ says a dive in demand for foreign exchange cash caused by New Zealand's border restrictions is behind its decision to stop buying and selling foreign cash.

The country's largest bank will stop buying and selling foreign cash from November 13 but will still accept cheques in foreign currency for now.

In a statement on its website the ANZ said border restrictions due to Covid-19 had seen demand for foreign exchange cash transactions fall significantly in recent months.

"As customers are well-served by other alternatives, including specialist providers and the ability to withdraw local currency from overseas ATMs, we have taken the carefully-considered decision to discontinue foreign exchange cash services in our branches."

ANZ customers will still be able to use their debit or credit cards to withdraw foreign cash at overseas ATMs.

The bank says the move only affects foreign cash and it will continue to offer other international services including foreign cash accounts, international money transfers and depositing foreign cheques.

It will also start charging a commission on foreign cash purchases after November 14 on its ANZ cashback platinum credit card.

Until October 1 it didn't charge a commission for foreign cash purchases on this card but it will begin charging 1.3 per cent after November 14, down from 1.8 per cent.

The bank has said people can still get access to foreign cash through specialist foreign currency exchange providers, using pre-paid foreign currency travel cards and through travel agencies.