Eritrea asks for Tigrinya
Eritrean offices work in Tigrinya, written in the Ge'ez script. A British record in English is unreadable to a clerk there until a Tigrinya version sits with it. A certified translation into Tigrinya in Birmingham supplies that version and leaves your English sheet exactly as it was issued.
The two are handed in as a pair. Nothing is stamped onto the English, nothing is removed from it, and it never changes hands. What you gain is a second sheet, signed by a named translator, that an Eritrean reader can act on directly.
Lead time in a small language pair
The practical difference between this route and a Spanish one is not price or method. It is availability. The pool of translators holding a recognised qualification in Tigrinya is small, so a job booked on the day it is needed competes for a narrow set of hands.
The fix is simple and costs nothing: say early. Give the date you are working towards when you first make contact, even if the scans are not ready. Work can then be placed against that date instead of against whatever gap happens to exist on the morning you send everything through.
The signature, the cost and the clock
An official Tigrinya translation in Birmingham is signed by a translator holding ITI or CIOL qualification, and their statement of accuracy names them and dates the work. This is the certified form UK authorities including UKVI and the GRO already accept, and it is what makes the sheet usable rather than merely helpful.
A certified translation for Eritrea is priced at roughly £25 a page and delivered in 2–3 business days as standard, with a 24 hours express lane where a date is already fixed. Send the whole bundle in one go and the spellings of names and places stay consistent across every sheet.