The SkyTeam alliance is marking its fifth anniversary by offering members of its partner airlines’ frequent flyer programs up to 20,000 bonus miles for international flights operated by SkyTeam carriers Aeromexico, Air France-KLM, Alitalia, CSA Czech Airlines, Delta and Northwest.

Members must register before Jan. 27 to participate.

Then, between Feb. 6 and April 30, registered members will earn 2,000 bonus miles for each eligible intercontinental flight segment, up to a maximum of ten segments.

SkyTeam members Continental and Korean Air are not participating in the promotion.