What are the Payment Services Directives and Strong Customer Authentication?

The Second Payment Services Directive (PSD2) 
This is a new EU directive regulating payment services in the European Economic Area. The directive requires new measures that impact how you access your account and pay with PayPal.

Strong Customer Authentication
It introduces two-factor authentication for online transactions, known as 'Strong Customer Authentication' (SCA). For online transactions in Europe and the UK, this extra security is coming to help keep online card purchases more secure and prevent fraud. 

What changes will I see when using PayPal?
Most of the time you'll log in or pay with PayPal by entering your email address and your PayPal password as usual. We may sometimes ask you to enter a one-time passcode which we'll send by SMS to the phone number you've registered with us or via a phone call if you have a landline.
What do I need to do?
Check that your current telephone (mobile and/or landline) number is correct in your PayPal account Profile. If we need to ask you for a one-time passcode we can send it by SMS to your mobile phone number or via phone call to your landline, so your payment or login won’t be delayed.
When will I need to enter this code? Do I need to do it every time I log in or pay?
Most times, we'll be able to verify your identity using the PayPal password you’ve typed and the device you're using (if it’s one of your usual devices). So, you may continue to login to your PayPal account or pay with PayPal as usual, using your email address and your PayPal password.
Where can I get this additional code? Isn’t it the same as my PayPal password?
No, the one-time passcode isn't the same as your PayPal password. We'll send you a one-time passcode by SMS or via a phone call to your landline each time we need a stronger verification of your identity. It’s important that you keep your phone details up to date in your PayPal account Profile to make sure this can work.
I've already enabled 2-step verification on my PayPal account, will I see changes?
2-step verification is authentication that complies with SCA. Hence, you won't see any changes when logging into your account. However, if you decide to disable 2-step verification, please make sure you have an up-to-date phone number in your profile before.
I don’t have a mobile or direct landline number to link to my PayPal account. Is there another way to verify my identity when logging in?
In order to continue to access your PayPal account in compliance with PSD2 regulations, you'll need to enable the 2-step verification setting from your settings profile page. This setting allows for more SCA compliant verification options. At this time, 2-step verification offers Mobile, Symantec VIP Security Key and Authenticator App.
What are Authenticator Apps and Security Keys?
An Authenticator App and Symantec VIP Security Key solutions generate a one-time passcode that you can use to sign in along with your password when you log in. After you download the authenticator app or Symantec VIP Security Key solution to your phone or desktop, scan the QR code displayed or enter the unique serial key on paypal.com to link them to your PayPal account. Once set up, the authenticator app and Symantec VIP Security Key will provide a one-time passcode that changes periodically.