Why the whole file has to read in English
A certified translation into English is required for documents used in Canada, which means every paper in a submitted file must be readable in English by the office that receives it. A certified translation into English in Belfast supplies exactly that for the documents which arrived in some other language, while the English-language originals in the same folder simply travel on unchanged.
Sorting the folder before spending anything
The useful first pass costs nothing at all: separate what is already in English from what is not, and count the second pile. People assembling a Canadian file often hand over the whole folder to be quoted, English certificates included, then pay for pages that never needed a word of work. Counting the foreign-language sides yourself turns a vague estimate into a figure you can check.
Belfast records and where they are issued
Because Northern Ireland maintains civil registration separately from the rest of the United Kingdom, a Belfast birth, marriage or death entry is issued by the General Register Office for Northern Ireland (GRONI) at Colby House, Stranmillis Court, Belfast BT9 5RR. Those certificates come out in English and therefore need no translating whatsoever — a fresh certified copy from that office joins the Canadian file exactly as it is.
What it costs and how long it runs
The rate is about £25 for each side as issued, applied only to the pages that genuinely require an English version. Standard turnaround is 2–3 business days from the moment legible scans exist, and a 24-hour route is available at a higher per-page rate when a date cannot be moved. Notarisation can be added on top where a particular file calls for that step.
Keeping the paper you cannot easily replace
Nothing in this process needs the physical document in anybody's hands. The work runs from colour scans, and where a Northern Ireland civil record is involved a fresh certified copy can be ordered rather than risking the one you already hold. A foreign certificate is the harder case, since replacing it means dealing with the issuing country all over again, so it stays in a drawer while its English version does the travelling.