In addition to the usual username and password, PayPal users can add another layer of protection by applying for a one-time-password (OTP) service.
The OTP system taps into the functionality of the VeriSign Identity Protection (VIP) Network used by 30 organisations around the world to authenticate users online.
Garreth Griffith, head of risk management at PayPal UK, said the optional service is aimed at offering extra assurance that users will not be victims of fraud.
"It is like a combination lock for your account designed to let you in and keep others out, with the extra safeguard that the combination always changes," he said.
Users can choose to get an OTP for each login either using a security token or via text message that can be sent to any mobile phone.
The UK is the fourth PayPal country to join the VIP Network after Germany, Australia and the US.