A TWENTY pence tip could turn into a bonus worth hundreds of pounds for two teenage waitresses.

Harriet Walker and Ailish Butland normally expect to share between £30 and £40 in tips after a busy day serving at Baldrys Cafe in Grasmere - but last Saturday an unwitting customer left a surprise gift in their gratuities jar.

As Harriet, 17, and Ailish, 15, counted their tips they discovered one of the 20p coins had no date, which makes it worth many times its face value.

Harriet’s father and cafe owner Ron Walker said: “The day before we had read in a national paper about the 20p coins without a date being worth a lot, so the girls decided to check every coin as they counted their tips.

“It seems one customer had plonked it in the tips jar without realising its true value.

“Now we have been told it could be worth many hundreds of pounds. The girls have already been offered £400 by a local coin dealer.”

However, Harriet and Ailshya are hanging on to their coin for the time being.

“They’re keeping as an investment in the hope that it will become even more valuable,” added Mr Walker.

Tens of thousands of undated 20p coins were produced in error by the Royal Mint in South Wales - said to be the first undated British coins to enter circulation for more than 300 years.

The mistake arose after the date on the new 20p was moved from the ‘tails’ to the ‘head’ or Queen’s side when the UK’s coins were redesigned last year.

Thousands of coins were minted using the old version of the Queen’s head, which does not have the year date.

A Royal Mint spokesman said: “The Royal Mint can confirm that a small number of new design 20 pence coins have been incorrectly struck using the obverse from the previous design, resulting in these coins having no date.

“The issue has now been resolved and the Royal MInt would like to reassure members of the public that thse coins are legal tender.”