One certificate, and no stage after it
An apostille is the correct and sufficient certification for documents used in Oman, so this corridor has one certifying stage and no consular one. The Legalisation Office (Foreign, Commonwealth & Development Office) issues the certificate for the whole country, working by post. Once it is attached the paper is ready for whoever asked for it, with nothing further to arrange on either side.
Membership since 2012
Oman joined the Hague Apostille Convention in 2012. Membership is precisely what makes a single certification enough between two countries: each side agrees in advance to recognise the other's certificates without demanding a further endorsement. None of that turns on the kind of document involved, so a birth entry and a board minute follow the same short path from here.
The issuer sets the starting point
Where the route opens depends on which body created the paper, rather than on where the person holding it lives now. The register office reprints civil entries recorded in Stoke-on-Trent; an entry recorded in another district is reissued by that district. Degrees come from universities and company papers from the company, and each of them must carry a signature before certification is possible.
This matters most to people who have moved. A certificate collected years ago in another town remains that town's record, and asking a local counter to reprint it leads nowhere. Settling that question first removes the commonest cause of a wasted fortnight on what is otherwise a short and predictable route.
Cost and pace
The charge lands per document — £45 by standard post, or £40 on the next-day service for registered businesses — so the bill is set by the number of sheets and not by how thick the envelope turns out to be. The clock is mostly transit, in both directions, and with no second stage sitting behind the first the whole timetable stays short.