Simple, the original neobank, is being shut down ahead of parent BBVA USA's acquisition by PNC.
In a message to customers, Simple says BBVA has made the "strategic decision" to close the digital bank, with accounts moved to the parent firm.
In November, PNC agreed to buy the US unit of Spanish giant BBVA in an $11.6 billion deal.
Simple was founded after Josh Reich pitched the idea to co-founder Shamir Karkal more than a decade ago, spotting an opportunity in the widespread public disillusionment with traditional banks in the wake of the 2008 economic crisis.
With a strong background in technology, the Simple founders believed that they could do better, and in the words of one-time CTO Alex Payne, build "a bank that doesn't suck".
After several years during which the idealistic team discovered the complexities of the banking market, Simple opened its virtual doors to much fanfare in 2012.
But, having pitched itself as an outsider, the startup quickly became subsumed into the big banking world, acquired by BBVA in 2014 for $117 million, albeit continuing to operate as a standalone business.
Reich and Karkal have both since left the firm. On Twitter, the former says he has no insight into the decision, but "I suspect PNC is prioritizing their existing online banking tech".
The Portland-based firm, which at one stage employed more than 300 people, has not provided details on potential layoffs.