The easyJet website and telephone messages make it seem as though you can only book a hold bag online. But if you try to book a bag going one way only when you have a return flight booked, you'll find it automatically adds a bag going both ways.

There seems to be no way round this - unless you do what it tells you not to, and ring easyJet. The number is 0330 365 5000. They can book you a hold bag in one direction at half the price of a return.