Every mark on the page counts
A paper bound for Angola is read as a whole object, not as a block of text. The date box, the registrar's seal, the reference number down the side, the second stamp pressed over a fold — all of it carries meaning. So the Portuguese version follows the layout as well as the wording, and says in square brackets where a mark sits and what it reads. Nothing is quietly dropped for being hard to make out.
Angola reads Portuguese
A certified translation into Portuguese in London is required for papers that will be used in Angola, whatever language they started in. English on its own is not enough for an office there to act on. The Portuguese version is the working copy: it is the one a clerk reads, and the English page beside it is there so names, dates and numbers can be matched back to the source.
The name behind the text
The certificate of accuracy is a short signed statement, and it is the part that turns a translation into an official record. A certified translator writes it, names the paper, and dates the signature. From that point the Portuguese is that person's claim, not yours. If a name is spelled two ways on the source page, the translator says so on the certificate rather than picking one and hiding the difference.
Pages and days
Cost follows the paper, not the file: £25 a page, counted by printed sides. Standard work runs 2–3 business days, measured from the moment a readable scan lands, and the express route brings that down to 24 hours. Notarisation can be added as an extra step where a file calls for it, though the signed certificate carries the Portuguese on its own.
Your paper stays where it is
Nothing about a certified translation in London for Angola needs the paper in your drawer to go anywhere. Scans do the job. Where the record is a civil one, a fresh certified copy from Westminster Register Office can stand in for the one you hold, so you keep the sheet you may need again. Ordering that copy early is worth doing when a date is close, because the translator can start as soon as a clean scan of it lands.