Soak a sponge in cold water and wring it out. Sponge the stain to remove as much ketchup as you can.
Mix ¼ tsp. of liquid dish soap with 1 cup of lukewarm water.
Blot the solution over the stain until it's gone. Rinse the area with clear water from the sponge. Don't saturate the carpet or upholstery.
Continue applying soap solution over the stain and rinsing with water until the stain is gone. If the stain is still visible, continue to the next step.
Mix 1 tbsp. of ammonia with ½ cup of warm water. Blot the solution over the stain until it's gone. Don't saturate upholstery. Rinse the area with water from a sponge and let it dry completely. If the stain is still visible, continue to the next step.
Mix 1 cup of white vinegar with 2 cups of warm water. Blot the solution over the ketchup stain until it's gone. Rinse the area with a damp sponge.