N26 Bank SE, doing business as N26, and formerly named Papayer GmbH, and Number26 GmbH, is a multinational German fintech and neobank company based in Berlin that offers a variety of financial services to individuals and businesses. N26 was founded in 2013 by Rocket Internet, an incubator, and operates in various European Union member states that are members of the Single Euro Payments Area (SEPA). Their services include transaction accounts and debit cards, as well as overdraft and investment products under a subscription business model.

The name of the company is derived from the number of smaller cubes in a complete Rubik's Cube, since a 3x3x3 cube has 26 individual visible cubes (27 minus 1 hidden).

Founded in August 2013 by Valentin Stalf and Maximilian Tayenthal as a fintech startup under the name Papayer GmbH, N26 initially offered a prepaid Mastercard financial management solution aimed at teenagers, which was launched in February 2014. During an interview with Business Insider later that year, the founders said that their service represented a niche market after receiving many inquiries regarding the availability of a similar service for adults. Subsequently, after securing €2 million in seed funding during June 2014, they changed their name to Number26 and discontinued the teenage finance service to work on a broader transaction account service for general use.

N26 launched their banking product on October 20, 2014, in a private beta. Shortly after launch, they received €10 million in a Series A round, at which point the service has been available in Germany and Austria. During their initial operations, N26 did not hold a banking license; instead, it provided an interface to a backend provided by Wirecard. In July 2016, it re-branded as N26 Bank, after receiving a banking license they applied for 9 months prior by the German regulator BaFin. The company stated that they will start operating on their own infrastructure in autumn that year. At this point, they had over 200,000 customers.

In June 2016, N26 terminated a number of customer accounts. The company said that reasons for these closures included suspected money laundering and excessive ATM withdrawals, with some customers making 15 to 30 withdrawals per month. N26 explained that while it offered free withdrawals, it incurred a cost of up to €2 per withdrawal in Germany, and that the volume of withdrawals by some users created a financial burden that could not be sustained across its customer base. The same month, N26 raised $40 million in a Series B round.

When N26 started asking customers to transfer their accounts to the bank's own infrastructure in November 2016, customers had to get a new account IBAN. Accounts previously held by Wirecard would be terminated. However, many customers reported issues during account migration, with many issues to get in touch with their customer support. N26 apologized and was transparent about what happened, saying they were overwhelmed by a large amount of customer support queries, even after initial preparation. However, they did not comment on other reported issues such as funds going missing and other software bugs.

N26 made transaction accounts available across 17 Eurozone countries in December 2016. Shortly after, N26 reached more than 300,000 users in March 2017, at which point they were processing over 10 million credit card transactions per year, with a transaction volume of over €3 billion.

Following this, N26 raised $160 million during a Series C round led by Chinese internet giant Tencent Holdings and Allianz X (Allianz) in March 2018. During this time, N26 claimed to have a customer base of 850,000, aiming to have 5,000,000 customers by 2020. This was followed by an additional $300 million in funding in January 2019 as part of a Series D round led by Insight Partners with Singapore's sovereign wealth fund GIC and a few existing investors also participating, putting N26 at a valuation of $2.7 billion. With its new valuation, N26 overtook Revolut as the most valuable mobile bank in Europe.