Baggage allowance on domestic flights is limited to 20 kg.
A fee of maximum $2USD per kg for domestic flights and $5/kg for international flights is charged for excess luggage but most of the time, if it is only a few kilograms extra, the airline waives this fee. Your guide can give some help in such situations.
Each passenger can carry onboard a free baggage allowance: one piece for economy class passengers. Each piece has a maximum weight of 7kg and the sum of three dimensions shall not exceed 115 cm (30 cm x 60 cm x 18 cm) or (12 x 24 x 7 inches). Airlines may refuse to carry unchecked baggage and may require the passenger to check their baggage in case it exceeds the quantity, weight and dimensions as specified above.