Preparing PayPal & 3DS
In a recent discussion with PayPal we learned about changes coming to their product line as a result of current 3DS adoption in the UK, EU and expected adoption in the future. This appears to be most relevant to merchants using PayPal Pro.
Currently, merchants in the UK and EU using PayPal Pro will experience an increase in declines as a result of 3DS enforcement. While the absolute number of CiviCRM users in both areas is low to modest, there are several rather large users, so the payment volume is sizable.
PayPal Pro does not support current 3DS parameters (version 1.0) and will not support future versions (version 2.0 arrives in October iirc). In essence, PayPal Pro does not support 3DS. In fact, they are phasing it out in favor of PayPal Commerce (venmo, apple pay, etc.), which is 3DS compliant.
PayPal expects 3DS enforcement to arrive in more countries such as CA and AU next, followed (eventually, ahem) by the US.
PayPal products that do not support direct card payment, i.e. Express and Standard, are not affected.
PayPal is advising partners to notify their merchants of the impending change and is recommending that partners build integrations with PayPal Commerce (or braintree, though they recommend Commerce for nonprofit organizations).