You do not provide any detail.
If it is a general circulation coin, it is worth nothing. Modified coins are worthless. There were no British Coins minted with holes in the centre.
On the other hand, you may have a medallion of some sort.
Belgium coins with a hole in the center are the 5, 10, and 25 Centimes. The value of these coins minted in 1905 ranges from $1 to $3.
It wasn't done at the mint. Someone may have drilled a hole to hang the coin on a lanyard, to use it as a washer, or even because they had too much time on their hands. Unfortunately the hole destroys any collector's value the coin may have had.
18mm It was decided in a meeting by someone putting a coin from the Netherlands on the table and said that size would do.
One cent (Canadian or US since the exchange rates are so similar). 1975 is a common date and only worth a penny regardless of the shape it is in. The hole was created after the coin left the mint and so the coin is damaged and worthless to a collector.
No it's the hole that kills collectible value. If the coin is silver it has scrap value
It gets bigger
The hole was used to tie a string in order to recover the coin once the coin was used in a vending machine .
You are asking about a 5 cent coin (KM#37) from East Africa. The coin is made of bronze, weighs 5.77 grams, and is 25.3mm in diameter, with a center hole about 7mm in diameter. The obverse (front) has a crown above the center hole and "FIVE CENTS" below the hole. Fleurs are on either side of the center hole, and "QUEEN ELIZABETH THE SECOND" is written around the edge. On the reverse (back) of the coin, tusks surround the center hole, with "EAST AFRICA" on the top edge, the denomination "5" below that, and the date "1955" on the bottom edge. 2,000,000 of these coins were produced in 1955. According to the Standard Catalog of World Coins, and example is worth US$0.10 in Fine condition, US$0.25 in Very Fine condition, US$0.75 in Extremely Fine condition, US$2.00 in Uncirculated condition, and US$3.50 in Brilliant Uncirculated condition. A small number were are also produced in Proof - an example would be valued at about US$150.00.
The hole in the 25 peseta coin was a traditional design feature dating back to ancient times when coins were strung together for easy carrying. It was also believed to help distinguish the coin from counterfeits.
The hole kills the collectible value of the coin. It's likely only worth about $25.00 for the silver content of the coin. Take it to a coin dealer for an assessment and value.
Just about where the center of the hole is.
Probably a 50 Yen coin from Japan