Find a hard-to-see area under the couch from which to cut a small piece of fabric. Match this vinyl fabric sample to a cream-colored iron-on patch at a local hobby or fabric store. Pick a patch that is the same color and thickness of your vinyl. Cut the patch slightly larger than the tear.
Squeeze the vinyl patch through the tear. Use a chopstick to push the patch through the tear and smooth out the corners. Make sure that the patch is adhesive side down.
Set your iron to a low setting or, if it has vinyl as an option, set the iron to the vinyl setting. Iron on half of the patch. Press the iron over the vinyl for 10 seconds and lift up to test if the patch has adhered.
Fix the patch if it has moved out of place during ironing. Iron the second half of the patch.
Apply a fabric adhesive around the perimeters of the tear. Press down on the adhesive for one minute to ensure the couch fabric and patch have bonded. Allow the adhesive to dry before using the couch.