LONDON — App-only startup bank Monzo is down — and normal service might not be resumed for hours.

Monzo notified users on Sunday that it is having issues with a supplier that may not be resolved until “nightfall.” The company is providing regular updates on its website.

The problems, Monzo said, are affecting card payments, top ups, and sending money. Some 120,000 people have a funded account with the company, according to an investment deck seen by Business Insider this week.

Monzo said: “One of our suppliers needs to run an unexpected, large migration and we are waiting for further information. We don’t have a firm estimate when this will be completed and suggest everyone uses another card today.”

International money exchange startup Revolut is also being impacted. “Our card payment processor is experiencing an issue, which is causing card payments to fail,” the company tweeted on Sunday.

Monzo users are tweeting their concerns about the disruption.

Monzo has told its investors it wants to reach one billion customers worldwide. It is currently running a crowdfunding campaign to raise £2.5 million, alongside £19.5 million raised from institutional investors.

This story is developing.

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