GURPS Dungeon Fantasy, out of the box, severely limits the Teleport spell. It forbids it outright, unless you spend a boatload of points for the privilege of a limited version, and you can't do that until later.
Why? Largely to limit mages ferrying people around, bypassing all physical obstacles, and going back to town at will to replenish supplies. GURPS doesn't limit you to once a day only if you get to 11th level, you can start with this spell and use it over and over. I've run a game with teleport, and "teleport across the entire campaign map to go pick up some rations and potions" happened pretty often. It could be fun, but it made dungeon obstacles a joke.
So DF bans it because it takes a good part of the challenge out of dungeoneering.
Over on the GURPS forums, Kromm suggested a way to write up the spell if you do want to include it.
Here is the whole thread: Limited Teleport for DF
Here is his writeup: Teleport writeup for DF
Short version? Can't see it, can't go there. And BAMF!
Note to my players: I may consider using this, but I'd replace the listed prereqs to "Magery 3, IQ 13+ and spells from 10 different colleges." Why? Really limits it to dedicated wizards, not to guys who pick up some wizardry just to teleport.