Hand lug gage can always be taken on board free of charge, up to two pieces. The larger one measures 56 x 45 x 25 cm, while the smaller one must fit into the 40 x 30 x 15 cm size. The weight of both items together is limited to a royal 23 kg.
Checked baggage is only included on selected long-haul flights, most of which are to Asia or Africa. On all routes to North America, checked baggage up to 23 kg is charged at 45 eur, if you buy in advance online via "Manage my booking" you will only pay 50 eur. On connections to South America you will then pay for checked baggage even 70 eur online / 75 eur at the airport. However, it is cheaper to buy a checked baggage fare directly from the British Airways website.
For short and medium haul flights to Europe or South Africa, the lowest fares include hand luggage only, with checked baggage being charged between 25 and 40 gbp per flight, depending on the destination. For flights in and around South Africa, there is a surcharge 290 zar (domestic) or 490 zar (regional).