Embassy legalisation for use in Chad
A British page means nothing to a clerk in Chad until a chain of marks says who signed it and that the signer was real. That chain is the service. To legalize documents for Chad you collect three marks in a set order: a notary's, the FCDO's, and one from the mission acting for Chad. Each mark certifies the one that came before it.
Chad consular requirements
The consular desk is the last and the fussiest of the three. Consular legalization for Chad turns on the bundle being whole and consistent: one spelling of each name, no page missing, the British certificate still attached. Loose staples and photocopies are the two usual reasons a set is handed back across the counter.
The Southampton to Chad route step by step
The notary comes first, because everything after that certifies a signature rather than the meaning of the words. The FCDO Legalisation Office, PO Box 6255, Milton Keynes MK10 1XX, then certifies the notary by post. There is no counter to walk into and no regional branch anywhere in the country. Last of all, the mission acting for Chad stamps the British certificate.
Cost and timing for this route
Costs come in three parts and only one is fixed: the FCDO takes around £45 per document. Time comes in two parts. The British legs run 7–10 business days, or 2–3 business days on the express route. The consular leg has no published clock at all, so treat any promised date as the earliest one rather than the likely one.
What the Chad side asks for
Embassy attestation for Chad is wanted most often when someone takes a job there, marries, or registers a company. Papers travel as sets: a degree with its transcript, a birth entry with the passport page. Document legalization for Chad also runs on originals. A scan is fine for a quote and useless for the chain, because it carries no signature for a notary to witness.