London (CNN) -- There's a treat in store for anyone in Britain whose baby arrives on the same day that Prince William and his wife, Catherine, deliver a royal heir -- the gift of a coin from the Royal Mint to celebrate the birth.
The silver penny will be dated 2013 and come in a blue pouch for a boy or a pink one for a girl.
The Duke and Duchess of Cambridge are expecting their first child in the middle of this month. They have opted not to know the sex of the baby before it shows up.
According to sources familiar with the plans, Catherine will give birth in the private Lindo Wing of St. Mary's Hospital in Paddington, west London, where William was also born.
Thanks to a change in the ancient laws of succession, their child will be next in line to the British throne after William and his father, Prince Charles, regardless of its gender.
To claim the silver coin, UK parents whose baby's birth coincides with that of the royal baby will have to register through the Royal Mint's Facebook page and upload a scanned copy of the birth certificate within 60 days. It is making 2,013 of the coins available.
The Royal Mint says the gesture reflects the tradition of marking a new birth with a gift of silver for good luck.
"The birth of the royal baby will be a joyous occasion not just for Their Royal Highnesses The Duke and Duchess of Cambridge but also for the whole nation," said Shane Bissett, director of commemorative coin at the Royal Mint.
"However, it will also be a special day for many mothers and fathers across the country as they too welcome the arrival of their new baby, hence why we wanted to extend this historical moment to them with a lucky silver penny."
The Royal Mint has been making UK coinage for more than 1,000 years.
For the past six decades, all newly minted UK coins have featured the portrait of Queen Elizabeth II.
On June 2, the Royal Mint marked exactly 60 years since her 1953 formal coronation by minting 2,013 commemorative gold sovereign coins. She had ascended to the throne the previous year.
The royal baby will also one day lend its face to the nation's small change as monarch.
CNN's Saskya Vandoorne contributed to this report.