The Silver Dominion
The great and grand Silver Dominion has a steel clad stranglehold on the continent's metal economy. In possession of WWI era industry and technology themselves, they keep their vast array of subjects in the bronze age, responding to attempts to forge iron or mix gunpowder with extreme prejudice, and the thievery of technology with draconian, scorched-earth measures.
The Dominion has little interest in how their subjects govern themselves, with many Kingdoms, Confederations, and City-states under their rule. They simply demand that they each provide food and laborers as taxes per their population. The Dominion's true method of control is popular support. You see, the Dominion is the self appointed protector of the continent, quelling any infestation of monstrous creatures where they may spread. But the real popular support comes from the "Copper Ration". Each citizen gets a certain number of copper coins per year from the Dominion. These go directly into the hands of the citizens, not by proxy via their local governments.
Question
But, in a far away coastal Bronze Age City-State Republic, how will the Dominion representatives ensure that each citizen gets their ration exactly once per year? The the logistics and politics of distribution itself isn't of interest, but how to make sure no one gets double rations.
More Context from Questions
As a specific example, the Dominion might once per year dock a warship in the harbor of a city. On the docks, each citizen must come and get their ration of copper coins. But how can the Dominion distributers ensure that each person hasn't already come through the line?
The Solution
When the Dominion docks their warships outside of the coastal city, setting up dozens of lines on the docks for people to receive their ration, each person first presents their "Nickel", a nickel coin inlaid with copper with their birth name and other identifiers, far too metallurgically difficult to recreate without machinery. This ID (as described in Nosajimiki's answer) helps to pit the people against their local government in favor of the Dominion, and helps with Logistical concerns. They are then marked on the cheek with indelible ink to ensure that they don't come back through. In this way, the Dominion both is able to manage handing out the coins, and also better accomplishes their goal of garnering popular support.
