Two roads out of Britain
One road ends with a single slip that Convention countries agree to read on sight. The other runs on through a foreign desk that adds a stamp of its own. Côte d'Ivoire sits on the second road, so document legalisation for Côte d'Ivoire is the phrase that fits the errand, and an apostille alone leaves it unfinished.
Where Côte d'Ivoire stands
Côte d'Ivoire has not joined the Hague Apostille Convention. An apostille issued in Derby for use in Côte d'Ivoire will not be taken as complete, and there is no version of the British mark that changes that. What actually applies is an apostille from United Kingdom to Côte d'Ivoire followed by a consular stamp, in that order, with a wait in between.
How the British half is done
Derby Register Office at Riverside Chambers, Full Street, Derby DE1 3AF can issue a fresh certified copy of a local civil record, and that copy is the sheet worth posting. The FCDO Legalisation Office, PO Box 6255, Milton Keynes MK10 1XX, then fastens its certificate to the sheet and returns the pair. Neither office is somewhere you can call in and wait.
What the first half costs
The Legalisation Office charges £45 per document by standard post, or £40 per document next-day for registered businesses. Because the unit is the document, the bill grows with the number of sheets rather than the number of trips to the postbox. Anyone reading up on what you need for an apostille for Côte d'Ivoire should add an allowance for the consular charge that follows.
One object, not loose sheets
Once the certificate is attached, the sheet and the slip are a single item with a shared reference. Pulling them apart, adding a cover page or swapping in a cleaner reprint all break the link that the next desk is relying on. Store the bundle flat, keep it dry, take a picture of it for your own file, and hand it on in one piece.