Hi Dan who are you looking for?
What county and name, age etc.
You can either go via the church route as linell says if you know which Church they are likely to be buried at.
Or you can go via the GRO online or by post (think they do it by post) I go online.
Or you can go via a local registry office to where you believe you have found the death registered in.
Some of the local regis offices offer an online facility and they normally check 2yrs either side of the year you believe the person died( but you need to check that as different regis offices might operate differently)
As Linell says you can say that you only want it if the person is aged about 55yrs for eg .
Some of us have access to quite a bit of info so flag the name you are looking for and we might be able to help.
ps with the GRO they will charge £7 but if you specify a check on the ancestor ie I only want it if so and so...they will charge £4 if they then dont find it but you have given a particular GRO ref. So I prefer the local offices.
If it is a Dudley one the wmbsgh website is very good.