Swedish is what Sweden reads
Swedish offices work in Swedish, so that is what your paper is turned into. A certified translation into Swedish in Sheffield is written from a scan and comes back signed and dated by an authorised translator. Your English document is untouched by any of it, and the Swedish pages are meant to be read next to it rather than in place of it.
Four stages, not one
People picture a single act of writing, which is why a two to four day wait can feel long for a short certificate. There are four stages. The scans are read and the page count fixed; the Swedish is written; the whole thing is read back against the source; then it is signed and dated. Each stage has to finish before the next can start.
The reading back is where the value hides. Prose errors tend to announce themselves, but a transposed digit in a reference number or a date written in the wrong order sits there looking perfectly reasonable. Catching that costs an hour of slow, boring comparison, and it is the hour that keeps the file from bouncing back to you from Sweden weeks later.
What speed can and cannot compress
Express work compresses waiting, not care. A job that would otherwise sit in a queue goes straight to a translator who keeps it until it is finished, which is how 24–48 hours becomes possible. The checking stage is untouched, because trimming it would defeat the point of paying a signer to put their name on the result.
Two things resist compression at any price. One is a page you have not sent yet, and the other is a question only you can answer, such as which of two spellings of your surname belongs on the file. Both stop the clock dead. Clearing them at the start is cheaper than buying speed at the end, and it costs nothing at all.
Cost and the page count
The rate is £25 a page and the count comes from the scans before writing begins, so the figure you hear on day one is the figure at the end. Standard work is 2–4 business days and express is 24–48 hours, and both routes end with the same signed, dated set. Nothing about the checking changes because you chose one or the other.