If you are travelling on piece concept route you may pay for the overweight bag if the bag weighs between 23-32kg (50-70lb). This can only be done at the time of check-in at the airport
Overweight option will allow you to upgrade one piece of your baggage from 23KG up to 32KG (applied for Economy Class customers) while the oversize option will allow you to upgrade your maximum baggage dimensions from 158cm (62in) to 300cm (118in.
Please click the link below to check excess baggage rates
For other enquiries contact your local offices, contact details can be found in the following link https://www.qatarairways.com/en/worldwide-offices.html