UK fintech Starling Bank has doubled its valuation to £2.5 billion ($3.3 billion) in a new funding round.

The London-based challenger bank, which was founded in 2014, has secured an additional £130 million in an extension to its Series D that first closed at a £1.1 billion valuation in March 2021. The startup has amassed more than 2 million users and boasts around 350,000 business accounts.

Starling, which counts US giants like Fidelity and Goldman Sachs among its investors, has planned to go public through an initial public offering (IPO) in London later this year or in early 2023. The company is willing to dedicate the cash to fund its growth through acquisitions.

The funding was filed on Companies House and subsequently confirmed by Starling to Insider.

"This will enable us to continue our growth and to build a war chest for acquisitions," a spokesperson said. "We are looking at a number of potential targets."

The fintech raised the funds from both Goldman and Fidelity as well as other existing backers, including the Qatar Investment Authority, the UK's railway workers' pension fund Railpen, Merian Global Investors, and Chrysalis Investments.

The extension comes in the midst of a positive period for UK fintech, with rival Monzo also increasing its valuation in a $500 million fundraising in December.