During WW2 rationing, once a person used their ration stamps to purchase something, say a pound of butter, what did the grocer do with the stamps? Did the government reimburse them the price of the goods?
Or did the people pay on top of using their rations?
Ration stamps didn’t work the way you think.
How did people receive ration stamps? Via Ames Historical Society
To get a classification and rationing stamps, one had to appear before a local War Price and Rationing Board. Each person in a household received a ration book, including babies and small children who qualified for canned milk not available to others.
Who issued ration stamps? (Via “United States Goes to War - Lee Kennett)
The work of issuing ration books and exchanging used stamps for certificates was handled by volunteer workers selected by local officials.
What did ration stamps do?
So ration stamps weren’t like food stamps. You couldn’t use them as a monetary source to buy food, instead the stores wouldn’t sell you the food unless you had one. Many grocery stores at the time were constantly low on supply, so they welcomed them. They couldn’t restock their shelves unless they provided suppliers/the government enough stamps.
Similarly,
Restaurant owners and other merchants were accorded more availability, but had to collect ration stamps to restock their supplies. In exchange for used ration stamps, ration boards delivered certificates to restaurants and merchants to authorize procurement of more products.
Different types of stamps:
Red stamps were used to ration meat and butter, and blue stamps were used to ration processed foods.
What happened if someone didn’t have enough money for a full ration stamp and needed change?
Originally there was no way for citizens to receive any form of change for the rations they couldn’t fully afford. The government acted and to enable making change for ration stamps, they issued "red point" tokens to be given in change for red stamps, and "blue point" tokens in change for blue stamps. The red and blue tokens were made of thin wood material, because metals were...well spoiler...being rationed.
Fun Fact:
There was a black market in stamps. To prevent this, the OPA ordered vendors not to accept stamps that they themselves did not tear out of books. Buyers, however, circumvented this by saying the stamps in the poorly made books had fallen out.
The stamps weren't currency, they were permission to buy the rationed good. So you had to pay for the good, as well as present the stamp.
The instructions with the US 1942 ration stamps said:
8 - When you buy any rationed product, the proper stamp must be detached in the presence of the storekeeper, his employee, or the person making the delivery on his behalf. If a stamp is torn out of the War Ration Book in any other way than above indicated, it becomes void. If a stamp is partly torn or mutilated and more than one half of it remains in the book, it is valid. Otherwise it becomes void.
Since the now torn out stamp was void, it could be thrown away.