You can purchase excess baggage using Qmiles or Qcredits* while making a booking on qatarairways.com. On the booking confirmation page, select “Purchase excess baggage” from the “MANAGE FLIGHT” menu to proceed. On the purchase excess baggage page, simply select your preferred payment option (Qmiles/Qcredits), desired excess baggage weight and complete the transaction.
If you have already purchased your ticket you can redeem for excess baggage in 3 simple ways. click here for details