Wrong. Unless location control has been disabled in every favorite list, you still need to set your location, or the scanner won't know if the stuff in the favorite list is in range.
Also, paying the seller to program the scanner for you is pretty much a scam. All they are doing is making a second copy of stuff already in the database that you get for free with the scanner. Unless they programmed stuff not in the database, you basically lit that money on fire.
If you ever plan to scan the entire database, which on occasion I do with my 536, entering a zip code is necessary so that you're not scanning agencies you'll never receive. Better yet for improved accuracy, get your exact GPS location and enter that instead. That said, without location scanning activated, you may actually be able to receive transmissions that would normally be skipped because you were outside of the intended transmission range. Of course, that is heavily dependent on the antenna you're using. We have to remember that, not so terribly long ago, scanners didn't rely on GPS programming. You would simply manually program the frequences you thought you could receive based on some guesswork. So provided that what has been pre-programmed into your 436 is within your current reception range, and as Jon says, location scanning is disabled, you should be OK with no zip code.