The language Botswana asks for
Botswana works in English, so English is the version an office there will read and keep on file. That single point decides whether you need this at all. A certified translation into English in Newcastle upon Tyne is for records issued in some other language — a birth entry from Angola, a marriage record from Mozambique, a school sheet from anywhere that does not write in English. If your paper is already English, hand it in as it is.
The certificate that Botswana accepts
No oath is taken for this route. The certification Botswana accepts is a signed certificate of accuracy: a dated statement from a certified translator, giving their name and stating that the English matches the source. It is simpler than a court appointment and it does the same job at the desk, because it puts a named person behind every line. Keep it stapled to the English text and the copy it was made from.
Per-page cost and turnaround
The rate is £25 for each page as issued, so counting your sides of paper before you send them tells you the cost in advance. A two-sided certificate is two pages. Standard work runs 2–3 business days once a clean scan arrives, and the express route closes in 24 hours. Sending a sharp scan rather than a dim photo is the cheapest thing you can do for the clock, since every unclear name has to be checked.
Keeping hold of the paper itself
Only the translation is certified; your record stays in its own form and stays with you. Newcastle Register Office at Civic Centre, Barras Bridge, Newcastle upon Tyne NE1 8QH issues a fresh certified copy of a birth, marriage or death entry, and that copy scans better than a folded sheet you have carried for years. The office works by post rather than over a counter, so plan a few days for a copy to reach you.
What the reader in Botswana sees
The clerk gets three parts in one set: the English text, a copy of the source page, and the signed certificate. They will glance at the certificate, then run an eye down both sheets to see that names, dates and reference numbers line up. Nothing is left out on purpose, so a seal with no words still gets described in place. Where a file needs more weight, the signature can also be notarised.