Embassy legalisation for use in Sudan
A Sudanese office will act on a British paper once a mission acting for Sudan has signed it. That is the whole of the requirement, and it is why people who legalize documents for Sudan cannot finish the job in Britain. The British certificate is a step towards that signature rather than a substitute for it, however official the certificate looks.
It also explains a frustration people meet halfway through. Embassy attestation for Sudan cannot be booked in advance and slotted in later, because the mission signs something that does not exist until the earlier desks have finished with it. The run only ever moves forward one stage at a time, and there is no way to overlap two of them.
The Cardiff → Sudan route step by step
Where the file starts depends on who issued the paper. Cardiff Register Office at City Hall, Cathays Park, Cardiff CF10 3ND holds the city's registers and prints fresh certified copies of births, marriages and deaths, which is the right opening for a civil record. Hold on to the sheet you already have, since it is the harder one to put right.
A degree, a contract or a sworn statement carries a private signature instead, so a notary or solicitor certifies it before the file leaves Wales. After that the route is identical for everything: Milton Keynes, then the mission. The kind of document changes the opening desk and nothing else about the journey.
Cost & timing for this route
One figure is fixed and one is not. Around £45 goes to the FCDO Legalisation Office for its certificate; the consular fee is set on the Sudanese side and added afterwards. Anyone budgeting for document legalization for Sudan should price the British stage exactly and leave a generous line for the rest of the run.
The practical lesson is dull but reliable. Order the copies you need, settle the language question, then let the file run without interruption. Every pause in the middle adds another postal leg, and the postal legs are what stretch a short errand into a long one.
Who is waiting at the far end
Searches for embassy legalization for Sudan from Cardiff tend to come from three places: a job, a family matter, or a business with a partner in Khartoum. Those are illustrations rather than a fixed list. What they have in common is a deadline someone else has set, and a file that has to cross several desks in order before that deadline arrives.