More than a quarter of the additional seats will be available from Exeter airport, where the airline and operator is basing an extra aircraft "to meet continued customer demand in the south-west".
Exeter will gain a new Tui route to Ibiza next summer, while its Tenerife and Lanzarote flights will operate year-round in future.
Tui will also start serving Antalya, Heraklion (Crete), Paphos and Rhodes twice a week from Exeter, opening up 10- and 11-night holiday options.