You can buy Qmiles anytime by logging into your account at qmiles.com. Buy Qmiles online starting from US$35 and going as low as US$30 per block of 1,000 Qmiles depending on the number of Qmiles bought in a transaction. To purchase additional Qmiles, you must have earned a minimum balance of 3,000 Qmiles since enrolment. Up to 60,000 Qmiles can be purchased per calendar year.
You can also buy Qmiles by visiting any Qatar Airways ticketing office but for US$50 per block of 1,000 Qmiles. Qmiles purchased are non-refundable.