It began around 1875. If you have access to a Mormon Family History Center the cheapest way is to order the film of the appropriate index and then order the film of the record you want. Most people don't need the official certificate which I believe is pricey.
The records are by parish so you need to know that first. If your person was in IOM 1881-1901 we could at least track down the appropriate parish via the census records.
I've never ordered a record from the government--I'm sure there is info re: that on the IOM site somewhere, if not one of the intrepid researchers will answer you.
Let us know if we can help you.
Donna