No, Venmo is not available in the UK. If you live in the UK and are sending money to someone in the UK: Square's Cash App is a good alternative to Venmo in the UK. But dozens of other innovative mobile peer-to-peer transfer options exist, like Revolut, N26, Monese, Monzo etc.
Is Cashapp available in the UK?
You can now send or request Cash App payments with friends located in the UK. When you send a payment outside the US, Cash App will convert the payment from USD to GBP based on the mid-market exchange rate at the time the payment is created and your recipient will receive the funds in GBP.
Is Zelle available in the UK?
Unfortunately, Zelle isn't available in the UK. But there are many other, even better alternatives. For example, there is the Starling digital bank that has free accounts.