The airline announced on Friday that it will increase fees on heavy bags, third bags and boarding position sales at airport gates as part of an effort to raise $1.1 billion in new annual revenue, Reuters noted.
Air fares at AirTran, which Southwest acquired last year, will also rise under the plan. Passengers who miss a flight with prior cancellation will be charged with a no-show fee.
The additional baggage fees could raise $100 million next year, the airline indicated.
Southwest is the only domestic airline that has not experienced a bankruptcy-enforced restructuring.
Earlier this week American Airlines, owned by bankrupt parent AMR (PINK:AAMRQ), announced that it will add new fees for optional flight rescheduling insurance options.
Shares of Southwest Airlines rose 1% in Friday afternoon trading.