SHENZHEN - One year after the first blockchain-based invoice was issued in the southern metropolis of Shenzhen, about six million such invoices have been issued, authorities said.

According to the tax bureau of Shenzhen, Guangdong province, the average daily issuance of the invoice is 44,000, with a total face value of 3.9 billion yuan ($554 million) for transactions covering 113 sectors.

So far, more than 5,300 companies in the city have registered to use blockchain invoices.

The use of blockchain-based invoices has been steadily expanding in the tech hub since a number of local restaurants, banks and supermarkets launched the service last August.

The service is now widely used in finance, retailing, catering and hospitality in Shenzhen.