Words with no exact match
Most of a record translates itself. Names, dates and addresses go straight across. Then you hit a term built into one country's system and absent from the other: a council office, a court with no French twin, a qualification named after the body that awards it. These few lines decide whether the French page is any use, and they take the most thought.
The language France requires
France works in French, so the whole record is written in French and the awkward terms cannot be left sitting in English. Each one is handled in the open: the sense given in French, the original name kept where it helps, and no silent guess anywhere. An official French translation in Plymouth is judged on those few lines far more than on the easy ones around them.
The two shortcuts to avoid
Two shortcuts tempt people, and both cause trouble. The first is picking the nearest French title and using it, which quietly changes what your record says about you. The second is leaving the English word untouched with no explanation, which leaves the reader stuck. Between them sits the honest option: say what the thing is, in French, and name it as the English named it.
Per-page cost and turnaround
The rate is £25 for each page of the record, counted from the paper you hold rather than from how long the French runs on. Turnaround is 2–4 business days once a clear copy arrives, and 24–48 hours if you take the quick option. A page thick with unusual terms costs the same as a plain one, so there is no reason to leave the hard parts out.