20p Coin Values UK: The 2008 Undated Mule & Other Rarities
Most UK 20ps are worth exactly 20p. But one famous minting error from 2008 — known as the "undated 20p" or "dateless 20p" mule — trades at 250 to 1,000 times face value. This guide explains how to spot one, along with every other 20p worth a second look.
The 2008 undated 20p — Britain's most famous minting error
For over 300 years no British coin had left the mint without a date somewhere on it. Then in 2008 the Royal Mint moved the date on the 20p from the reverse (next to the portcullis) to the obverse (below the royal shield). During the transition, a small number of coins were struck using the old obverse die (no date) with the new reverse die (no date) — leaving both sides dateless.
The Royal Mint confirmed the error in June 2009. An investigation by the BBC estimated 50,000–200,000 coins had been released. Because no records were kept of the exact die pairings, a precise mintage is impossible.
How to spot a genuine undated 20p
- Hold the coin with the Royal Shield uppermost — this is the post-2008 reverse.
- Check below the shield for a year. If you see one (e.g. "2009", "2010"), it is a normal coin.
- Flip the coin. On the portrait side, check the lower right of the Queen. Pre-2008 coins carry the date here.
- If neither side shows a year, you have an undated mule.
Other 20ps worth more than face value
| Type | Year(s) | Notes | Typical value |
|---|---|---|---|
| Undated "Mule" | 2008 | No date on either side | £50 – £200 |
| Proof (Royal Mint set) | 1982–present | Brilliant uncirculated grade from sealed set | £2 – £10 |
| Silver Proof Piedfort | Selected years | Double-weight, sterling silver | £40 – £80 |
Featured 20p coins on MyCoinage
