Before I talk about the legal side of things, I'll say that I think it's certainly a best practice to walk someone out the door with everything you need to give them so that they don't have to come back to the office. Any personal goods they may have (the "boxing up their desk on their way out" concept), any money owed, etc. They have unpaid vacation time or a refund coming from health insurance? Get those factored in and resolved on the spot too.

Generally, the thinking seems to be that once you tell someone that they're no longer part of the firm, whether they're quitting or fired, you want to walk them off the premises as soon as possible. No more "two week notice", it seems much more common to give that two week notice just to find that you're done and outta there an hour or two later.

I remember when I quit my last fulltime job, at Hewlett-Packard, I was rather surprised to find that my two week notice was ignored, other than that they include two extra weeks pay when they gave me a final check that afternoon. Kinda gave me a vacation, actually. But that's another story.

Now let's talk about the law, for just a minute, because it's obviously important. It turns out that, according to Findlaw.com, different states have different laws about paying someone upon termination of employment.

For example, in California, you must pay them immediately if you're firing them, but if they quit you have 72 hours, unless they've given you at least 72 hours notice, in which case, again, you'll need to pay them immediately.

On the other hand, in Delaware, Iowa or Kansas, you can wait until the next scheduled payday if they're fired or quit. Kentucky? Definitely not a worker's state: fired or quit, the company is expected to wait "until next scheduled payday or within 14 days, whichever is later". Yes, later. Nice, eh?

Your best bet is to check the Findlaw link, above, and then make sure you double check by calling your attorney as needed, especially if you have a sense that the employee might try to cause trouble or otherwise become a problem.

Good luck with your task. I've fired people and know firsthand that it's a very unpleasant job, perhaps the very worst one facing any manager.

Obligatory caveat: I'm not a lawyer, and this message should not be construed as legal advice in any capacity.