An elderly Southland couple was forced to flee their home after their couch caught fire early this morning.

The fire broke out at the house on Rata Rd in Otatara at about 2.10am. The couple had escaped the house by the time fire crews arrived, a Southern Fire Service spokesman said.

The house became "smoke-logged" as a result of the fire, the spokesman said.

The fire was put out soon after crews arrived and the couple was treated at the scene.