This article is from the Cats and the Outside World FAQ, posted to rec.pets.cats newsgroup. Maintained by Cindy Tittle Moore with numerous contributions by others.
One of the most common claimed reasons cats are left at shelters in the United States is because the owners are moving and either can't or don't want to take their cat with them. Moving can be difficult for a cat, but it isn't impossible. If you are considering not taking your cat with you and taking it to a shelter, keep in mind that your cat will only of many others in a shelter given up for the same reason. No one will take pity on your cat in particular, or consider it an especially 'good' potential adoptee just because it came from a home environment.
There are a variety of responses to a change in home location. Some cats do well, others are a nervous wreck for several weeks.
You might consider keeping your cat at someone else's home during the actual move-out. This way you will keep it out of the way, prevent accidental escape or injury, and spare the cat the trauma of seeing its world picked up and carried out. Otherwise consider keeping it confined to a crate or a single room to prevent accidental escape in the chaos of moving.
Once at the new place, keeping it for a day or so in one room of the new place before allowing it out to explore the rest of the house will alleviate its anxiety. In any case, be prepared for up to several weeks of "slinking" and hiding until becoming accustomed to the new place.
If you have a cat that goes outside, you will want to keep it indoors for about a month at your new place before you let it out. Cats have a homing instinct that takes about a month to "reset". If you let it out before this time, the cat may become disoriented and get lost, or make a beeline for the old home.
 
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