Fewer than you would have a few years ago. All new rapid chargers should already offer payment via contactless credit or debit card, and a lot of slower units offer one-off payments without registering an account.
However, this is usually the most expensive way to charge. Many networks offer discounts for account holders, and store payment details to make it quicker to start a charging session. Some memberships and fuel card providers also offer ‘roaming’ capability, which enables drivers to access and multiple networks with a single account. A few also offer international roaming.
A full guide to the UK’s public charging networks is available here.