Start from the date, not from today
Korean-bound files almost always exist because something has a date on it: an appointment, a term, a start of employment. That date is the fixed point and everything else bends around it. Written down first, it turns a vague worry into simple arithmetic — so many days for the writing, a day for reading the set, and whatever is left over is your margin.
Where the days actually go
The translation window is the predictable part. What varies is everything in front of it: locating the paper, ordering a clean copy when the one you hold is worn, and photographing both sides properly. Where the record is a birth, marriage or death entry, Derby Register Office at Riverside Chambers, Full Street, Derby DE1 3AF issues a fresh certified copy, and ordering that early removes the usual source of slippage.
What speed buys, and what it cannot
Express shortens the writing to 48 hours. It cannot shorten a wait for a document you have not requested yet, and it cannot make a blurred image readable. So the honest order of operations is to fix the paper first and buy speed second. A file sent complete on a Monday at the standard rate normally beats a rushed one sent on the Thursday.
The arithmetic on the invoice
The rate is £25 for each side as issued, which makes the bill easy to predict before anything is sent. Count the sides in the bundle, multiply, and you have the standard figure. Express adds a premium per page rather than a flat fee, so on a thick set the difference between planning ahead and paying to catch up grows with every extra sheet.