What you are actually sending
A criminal record certificate is issued as a paper document with a signature on it, and that signature is the whole point. The Legalisation Office does not read the content or judge what it says. It confirms that the signature belongs to someone it recognises, which is why the issued paper matters and a home printout does not.
Who stamps it, and from where
The Legalisation Office, part of the Foreign, Commonwealth & Development Office, issues every British apostille from a single address. There is no counter in Sheffield, or in any other city, and nothing about this stage is arranged locally. The file goes out by post and comes back the same way, stamped.
That is why the legalisation of a Criminal Record Check in Sheffield is identical to the same job started in Manchester or Bristol. The only local element is your own post, so the sensible approach is to send everything the application needs in one round rather than piece by piece.
Cost, and getting the sequence right
The official fee is £45 for each document by post, with a next-day route at £40 for each document available to registered businesses. Sequence matters more than price on this document. Obtain the certificate, stamp it, translate it if needed, and submit it, in that order. Doing any of those out of turn usually means paying twice.
Where it goes, and in what language
To apostille a Criminal Record Check in United Kingdom is nearly always part of a work or residence application rather than an end in itself. Teaching posts, medical registration, visa files and adoption cases all call for one, and each has its own timetable that the stamp has to fit inside.
Where the receiving office works in another language, arrange the translation once the stamp is on the paper. A translation done earlier covers the certificate alone and not the stamp that was added later, and a bundle where the two do not match is the most common reason the whole file is returned.