What the stamp does, and does not, say
The apostille speaks only about a signature. It confirms that the person who signed the paper is who the record says, and it says nothing whatever about whether the company is solvent, active or well run. Understanding that narrow scope explains why the choice of copy matters far more than the content of the document itself.
Choosing a copy the office can act on
The Legalisation Office works from a list of signatures it already holds. A copy issued by the public register of companies carries a signature of that kind. So does a copy certified by a solicitor or a notary, whose signatures are also known to the office. A plain internal printout carries nothing it can check.
This is the single decision that determines whether the job runs smoothly. Companies often send the version they have to hand, and it comes straight back. Sorting the copy out first turns the legalisation of an Articles of Incorporation in Sheffield into a routine postal errand rather than a repeated one.
Cost, speed and sending a full set
The official fee is £45 for each document by post, and £40 for each document on the next-day service open to registered businesses. Corporate work rarely involves one paper alone, so the fee multiplies quickly. Sending the whole set in a single round keeps the stamps dated together, which reads better to a foreign registry than papers arriving piecemeal.
Where the papers go, and in what language
To apostille an Articles of Incorporation in United Kingdom is almost always part of setting something up elsewhere: a branch, a subsidiary, a bank account, a tender. Those processes run to fixed dates, which is why the next-day route exists and why the paperwork is worth starting well before the deadline that prompted it.
Where the registry abroad works in another language, have the translation prepared after the stamp is applied. A translation made in advance describes the founding document alone, while the bundle now includes a government stamp as well. Where the two do not match, the file is usually returned before anyone reads the company details.