Southwest periodically make flights for further in the future available. They’ve added flights until August 6th, 2018. They have also made some changes to their flight schedule, you can read more about those changes here.
Southwest has a pretty good cancellation/refunds policy, depending on the fare you’ve booked you’ll either receive a credit towards a future flight(Wanna Get Away) or cash refund (Business Select or Anytime – returned to credit card if you used one). That means it’s often best to book flights as soon as they become available and periodically check to see if the price has decreased, if it has you can click ‘change flight’.
Hat tip to Miles For Family
How does it work if you book now, but earn a companion pass in 2018?
You can add it later as long as there are still seats available.
+1
You would have to call them to branch out your “now companion” ticket into a separate ticket which you can cancel, and get a “companion” ticket for free (almost).
Also if you do have points, but not a pass then it is a no brainer… fully cancellable and refundable tickets in that case (even if in AnyTime category).