For more than seventy years, Queen Elizabeth II served as the monarch of Great Britain, and either her initials or her image can be found on all sorts of things, from Marmite and A1 sauce to government uniforms, coins, and stamps. With the Queen's passing, each of those products will need to be changed to show the new monarch, King Charles III, but it might not be as costly as it sounds.

While thousands of post boxes in Britain bare the Queen's initials, they will only be replaced with boxes showing the King's initials as new boxes are needed. Similarly, stamps with the Queen's image will still be valid until they are replaced by the Royal Mail as a part of its existing plan to introduce stamps with barcodes over the next few years.

"The cost of a post box is not related to whether it's a change of monarchy or not," said Norman Baker, an author and former government minister. "The cost of Charles being on there rather than the Queen is minimal. I mean, it's nothing."

Along with stamps, individuals in Britain can still use coins and banknotes with the Queen's image. Sine 2016, the Bank of England has been transitioning away from paper towards polymer-based notes, and the currency showing the Queen will be replaced as a part of that process, likely over the course of four years.

On the other hand, changing the face shown on coins is likely to be more expensive. Unlike banknotes, coins are costly to produce, and there is no ongoing coin transition to help offset the cost. Mauro F. Guillén, the dean at Cambridge Judge Business School, told The New York Times that changing the transition from Queen Elizabeth coins to King Charles coins could cost around $600 million.

Taxpayers may foot the bill for the coin swap, but many of the products marked with the Queen's coat of arms are privately sold goods, meaning the brands themselves will need to cover the cost.

By supplying goods and services to the royal family for five out of the past seven years, roughly 800 companies have been awarded a royal warrant from the Queen. The warrant allows the companies to sell products showing the Queen's coat of arms. Now that the Queen has died, these companies have two years to change to the new coat of arms.

"We're not talking about changing the ketchup," Guillén said. "We're talking about changing a very, very small, tiny part of the packaging."

Changing branding might cost businesses, but the death of the Queen has also led to more sales for many companies, particularly those selling royal family memorabilia.

"All of a sudden, I suppose, just the everyday stamp has become a collector's item, and that's quite interesting," Laura Clancy, a lecturer in media at Lancaster University, told NYT. "It changes the meaning of the object, right? From an everyday object to something that is more special."