The mark that counts
A certified translation into Chinese in London is finished with a company stamp — a red mark pressed on the pages by the firm that produced them. Offices in China accept that form of certification, and the reason is simple: the stamp points at a firm rather than at a stranger's handwriting. Beside it sits a signed statement saying the Chinese matches the page it came from, dated, with a name on it.
Two scripts, one language
Chinese reaches the page in two written forms, Simplified and Traditional, and the certified translator works in both. Which one you need depends on the office that will read the file, so it is worth saying at the start. The wording, the stamp and the statement of accuracy are the same either way. Only the characters differ, and setting the text in the other script later costs time you may not have.
Chinese is what the file must be in
A certified translation into Chinese is required for papers used in China, whatever language they were issued in. An English certificate on its own gives a clerk nothing to act on. So the Chinese version becomes the working copy, and your English page rides along beside it — that pairing lets a reader trace a name, a date or a serial number straight back to the source without guessing.
What a page costs, and what a day buys
Pricing follows paper, not files: £25 a page, counted by printed sides. Standard work runs 3–5 business days from the moment a readable scan lands, which is longer than a short European job because the text is set character by character. The express route closes the same work inside 48 hours. An official Chinese translation in London is quoted from the page count you send, so a clean scan pins the cost down at the start.
The paper you keep
A certified translation in London for China never calls for the sheet in your drawer to travel. Everything runs from scans. Where the record is a civil one, a fresh certified copy from Westminster Register Office can stand in for the one you hold, which matters most for a birth or marriage entry you may need again years from now. Two copies also mean a spare if a reader keeps the set.