I have to send my Sig Mosquito back to Sig Arms to be fixed.  I can just send that through a UPS hub, since I am sending the pistol straight to the manufactuer, correct?  After it's fixed, do they send it right back to me, or to an FFL? Is there anything in the laws of NYS I should be aware of?

It's permitted to send the gun to the manufacturer for repair through UPS.  UPS requires you use priority overnight service (expen$ive).  Note your local licensing authority probably requires notice that you are temporarily disposing of a permitted handgun.  Failure to do so can result in loss of your permit.  Make sure to call and clear that issue before you ship.

(Quick enough?)

Holy crap, that was fast.  Thanks for the heads-up on the authority, I didn't even think of that.  I was just about to run out and send it too... thanks!
The good news: Sig has paid for the overnight shipping to and from, they sent me a UPS label.
The bad news: The pistol licensing office is closed now, so I can't get in touch.  I guess I'm waiting for Monday.

Let us know how you made out. Personally I've never heard of a licensing authority that required notification when shipping a handgun to a manufacturer or gunsmith for repair or customization. With some of the wacky things that have been posted recently I guess anything is possible though. They may even tell you you have to have it shipped by an FFL. It does sound like something NYC would require though.

RKBar15, you are exactly correct.  NYC requires notice before disposing of a pistol for any reason, even temporarily.  There may be other counties that require it as well.

I am not aware of Onondaga Co having that requirement. You only need to notify them if moving or if you actually dispose of the pistol (sell, trade, etc-which requires a bill of sale), or, yikes, lose it or  have it stolen.

You can ship it directly to the manufacturer for warranty repair, no FFL required.

Quoted: You can ship it directly to the manufacturer for warranty repair, no FFL required.

That's true but unfortunately some counties routinely make up their own rules as to what you can and can't do. NYS with its hodge podge county licensing system is probably the worst licensing system in the nation.

I have a buddy with a NYC permit that got his ticket yanked for just this reason.
They notified him to turn in all his firearms to the police in 24 hours. ( He had one other
pistol on his permit). He talked to a lawyer but didn't need him further seeing as he got a
quote, "firm but fare" investigator on his case. It still took over six months to clear up
this rules infraction. He didn't even know that this rule was in effect.

Quoted: I have a buddy with a NYC permit that got his ticket yanked for just this reason. They notified him to turn in all his firearms to the police in 24 hours. ( He had one other pistol on his permit). He talked to a lawyer but didn't need him further seeing as he got a quote, "firm but fare" investigator on his case. It still took over six months to clear up this rules infraction. He didn't even know that this rule was in effect.

How did the NYPD Pistol Licensing Division find out? I don't see how they would know unless he told them.

Ok, I called the Onondaga Sheriff's Pistol Licensing Unit, and there are no special notification procedures to ship my Sig to the manufacturer.  I have to declare it to UPS, and send it inoperable, which I guess means I need to lock it with the Sig supplied cable lock, and send it in (they should have the key or a pair of cutters).  She also said I need to inform the OSPLU if any major changes are made or if they replace my pistol with a new one.  Once again, the people at the Onondaga Sheriff's PLU were very pleasant and informative.  And thanks again Phil_A_Steen for reminding me not to assume and to check first.

Now let's just see how long it takes Sig to get her back to me...