With more venues in the US asking for proof of a COVID-19 vaccination and others offering perks, fake cards showing immunization are popping up.

A California bar owner last week was the first in the state to be charged with selling fake vaccine cards.

Todd Anderson, owner of the Old Corner Saloon in San Joaquin County near Sacramento, faces charges of felony identity theft and forging government documents as well as a misdemeanor for falsifying medical records, according to police.

People in the US who receive any of the three COVID-19 vaccines authorized by the Centers for Disease Control and Prevention, or CDC, get a card that lists the vaccine and the date and location of vaccination.

The California Department of Alcoholic Beverage Control said last week that its agents purchased the fraudulent cards numerous times in April at the location. The cards were sold for $20 each, according to USA Today.

There are also offers online selling the fake cards and calling them "freedom cards". A $40 listing on OfferUp included a photo of what appeared to be an "official" COVID-19 vaccination record card from the CDC, The Oregonian reported.

The FBI has warned against trade in fake vaccine cards. "If You Make or Buy a Fake COVID-19 Vaccination Record Card, You Endanger Yourself and Those Around You, and You Are Breaking the Law," says an FBI warning on its website. The bureau also advises people not to post images of their vaccine cards on social media to avoid having the information stolen.

In New York, a Democratic state legislator is proposing a law that would make forging or possessing phony vaccine documents a felony, Newsday reported.

Explicitly clear

The bill's sponsor, Assemblyman Jeff Dinowitz, said in a statement: "We should be explicitly clear in New York: If you get caught with a fake vaccination card, you will go to jail for a long time."

An investigative team at a Fox News affiliate in Cleveland responded to an advertisement online selling phony cards.

This was the response they received: "Hello thanks for contacting us. We produce and sell the COVID for $35 if you'll be taking from 5 cards and above plus $15 delivery fee while it's $40 if you'll be taking below 5 cards plus $15 delivery charges. As of now, we have CDC and NHS cards available only. Which of this do you need?"

The journalists replied that they did not want to buy one and asked the sellers if they knew it was illegal to sell the fake cards. "We're perfectly aware of the FBI warning, but our cards are registered with authentic 'Lot Number' ND it's practically impossible for FBI to distinguish our cards from other cards. Do you need the cards?"

The station said it filed a report with the FBI's internet crime complaint line.

While the administration of US President Joe Biden has made it clear that the federal government does not require people to carry proof of vaccination, many businesses, venues and events are increasingly offering special access or treats to those who can show proof of vaccination.

The real vaccine cards can get the holder some tangible benefits. Some sports teams let vaccinated fans sit in special sections without social distancing.