Most interior doors are made of wood or composite material. Planing wooden doors is one option for fixing a door that sticks. For minor adjustments you can sand the edge of the door.

You can usually tell from the scuff marks on the edge of the door where it is sticking at. Try sanding the spots until the door closes without too much friction. If you sand through to bare wood you will need to touch up the paint or varnish. It may take a little elbow grease to sand off enough material to matter.

For related information see, 'Troubleshooting Door Problems', 'How To Adjust Interior Doors' and 'Adjusting Exterior Doors'.

I do not recommend trying to plane the door unless you have some experience working with wood planes and doors. One reason is that unless the door is solid wood, it is probably made of a composite material. Masonite, plastic and mdf do not plane well at all. The other reason is that prehung doors should not need to be planed, the doors are correctly sized for the openings. It is more likely that it is sagging and needs to be adjusted.

If after adjusting and sanding, the door still sticks you can try running a couple of square drive trim screws (2 1/4” Screws should be long enough) through the jamb and into the framing. Do this at the location where the door is sticking. You may be able to draw the jamb in enough to relieve the pressure. Hopefully you have been able to get the door working freely for this repair on a prehung interior door.

Planing a door along with sanding may be needed if the door swells and will not close. However, this should be done cautiously, since taking too much off the edge of the door can leave gaps when the humidity is lower.

You can usually tell from the scuff marks on the edge of the door where it is sticking at. Try sanding the spots until the door closes without too much friction. If you sand through to bare wood you will need to touch up the paint or varnish. It may take a little elbow grease to sand off enough material to matter.

Do not try planing the door unless you have some experience working with wood planes and doors. It is easy to damage the door by taking off too much material. Make sure the door is not out of adjustment first. See the article 'Adjusting Exterior Doors' for more information.

If after adjusting and sanding, the door still sticks you can try running a couple of square drive trim screws (2 1/4” Screws should be long enough) through the jamb and into the framing. Do this at the location where the door is sticking. You may be able to draw the jamb in enough to relieve the pressure.