BERLIN (Reuters) - German smartphone bank N26 now has 5 million customers, the founder of Berlin’s leading fintech startup said, representing an increase from the 3.5 million users it reported last summer.

N26, last valued by investors at $3.5 billion, is growing fastest in its main European markets while the United States - where it launched last year - is making a positive contribution, co-founder and Chief Executive Valentin Stalf told Reuters.

“We added more customers in 2019 than we did in all the prior years put together,” Stalf, 34, added in an interview.

He declined to share financials or give a market breakdown, but said growth at N26 was strongest in Germany, France and Austria, while Italy and Spain had a chance to achieve a similar rate of expansion.

N26, founded in 2013, has raised a total of $683 million in investment. Its last funding round in July 2019 gathered $170 million backers including Valar, Tencent and Insight Partners.

(This story corrects value of company in paragraph 2 and the date of company’s founding in the final paragraph)