ZOPA means Zone Of Possible Agreement, a negotiating term specifying the bounds within which agreement can be reached between two parties.
ZOPA was one of the first P2P lenders in the UK and was started in March 2005 by James Alexander, Giles Andrews, Tim Parlett, Richard Duvall, David Nicholson.

Zopa used to host a yearly celebration in Central London for its lenders, so they can all meet and talk about finance. Basic RoI varies from 3.1% to 4.8% and is subject to variation. The Peer-to-Peer Finance Association was established in 2011, with Zopa as a founding member.