There are many many tablets that can attest to the fact that they had them. According to Dr. Tonia Sharlach at the University of Pennsylvania, lots and lots of things were taxed year round [Here's a whole article about the salt tax!], with payment of objects instead of money. This apparently led to a lot of smuggling, and Dr. Sharlach’s article quotes a letter from about 3900 years ago written by an office to an employee:
Irra’s son sent smuggled goods to Pushuken but his smuggled goods were intercepted. The Palace then threw Pushuken in jail! The guards are strong…please don’t smuggle anything else!
Apparently one of the worst taxes was the labor tax (sometimes called the “burden”). While it sometimes feels like a certain amount of my job amounts to a labor tax, it’s admittedly quite a bit nicer than being somewhere else to work for a few months.
Upcoming…why is tax day April 15 anyway?
The map was posted under GNU-FDL by Nareklm.