Almost half of Zip's customers are now based in the United States, where its newly acquired QuadPay grew revenue by 50 per cent and volume by 42 per cent in the September quarter, compared to the three months to the end of June.

Zip, which offers instalment payment options and more traditional credit products, said active customers hit 4.5 million, more than double the previous quarter as 628,000 new customers came onto the app. The Australian Zip business has 2.3 million, with QuadPay now accounting for 2.2 million.