How long does unopened powdered sugar last?

I am not sure because mine never lasts too long but.. here is what the web says....

What is the shelf life of sugar?
Sugar, properly stored, has an indefinite shelf life because it does not support microbial growth. Because C&H harvests its sugar cane year-round, you can expect optimum freshness and flavor at the time of your purchase.

source:
http://www.chsugar.com/consumer/faqs.html#q01

Thanks Natalie. I only ask because my pantry in Alabama is full of powdered sugar. I live in WA and am currently checking on my house in AL and was thinking about shipping my sugar to WA. I mean bags of it!!!

Get Them!!! you know they always get used...

Powdered sugar contains starch and other anti-caking agents: 2 years shelf life - check the packets for the date it was packaged or the "use by date" ..

Pure sugar is different - if stored correctly .. then indefinitely ..