SHENZHEN - One year after the first blockchain-based invoice was issued in the southern metropolis of Shenzhen, about 6 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.