Certain 50p pieces could be worth an astonishing £3,000, as it emerges a certain batch of coins were released with unique designs on them.
Beady-eyed coin holders could be hanging onto 50p pieces worth thousands more if they were released with a particular design on the back.
Ebay sellers have coins selling for anything between £4 for an Olympic games design to £3,000 for an original coin patterned with a swimmer's face on it.
What should you look out for on your 50 pence pieces? We detail which are selling for what prices.
1. London Olympics coins
If you're one of the lucky few who have this coin, you've hit the value jackpot.
These special edition 50 pence pieces were made during the London 2012 Olympics, with this particular one pictured going for thousands.
29 different games design coins were released, with some going for more than others depending on how many the Royal Mint released.
Should your coin have a swimmer's face on it, you're one of only 600 people to possess it - and it could sell for a whopping £3,000 online.
2. Peter rabbit coins
Reported to be the fastest selling coin collection by the Mirror , these pretty designs are going for higher than their face value.
If you're lucky enough to have one of the coloured ones, expect hundreds for one piece.
3. WWF collectors edition piece
This very rare 50p was released as a collector's edition, with special versions going for £1,000 on eBay.
But any version of this coin is worth a lot, with even standard circulated coins selling for more than £10.
4. The EC commemorative 50p coin
If you have one of these slightly larger 50p pieces, they could be worth at least £20.
No longer circulated, they were originally released as the normal size at that time before the 50p was made smaller in 1997.
5. Suffragette coin
Barely circulated when it was first released, this coin marking the achievements of the suffragette women can fetch a solid £20 or more.