Billionaire Peter Thiel-backed AvidXchange Inc is looking to raise up to $506 million in a U.S. initial public offering (IPO), according to a regulatory filing on Monday, that could value the business payments firm at about $4.4 billion.

AvidXchange was valued at $2 billion in a funding round in April last year. Reuters reported in March that AvidXchange had hired investment banks to prepare for an IPO.

The Charlotte, North Carolina-based company, which counts Mastercard Inc among its investors, makes software that automates payments, invoicing and accounting for small- and mid-sized businesses.

The 21-year-old company processed around 53 million transactions with a total value of $145 billion last year, its website showed.

AvidXchange has more than 7,000 North American companies as its clients and has offices across seven cities in the United States.

The company, which expects to list on the Nasdaq under the symbol "AVDX," said it plans to price its stock at $21 per share to $23 per share in the IPO.

Financial technology firms that facilitate payments for businesses have been highly successful over the past year, as the COVID-19 pandemic accelerated digital transformation across industries.