Can I transfer or exchange IPv4 addresses?
Yes. The RIPE NCC follows the procedures outlined in section 5.5 of ripe-553, "IPv4 Address Allocation and Assignment Policies for the RIPE NCC Service Region", which documents the process of transferring IPv4 addresses between RIPE NCC members.
The RIPE NCC Listing Service is a platform that enables RIPE NCC members to list for exchange the IPv4 address space they hold and no longer need. The listing service is only available to members and its use is included in the annual RIPE NCC membership fee.