Why the Tajik version has to travel too
An office in Tajikistan works in Tajik. An English record hands a clerk there nothing it can act on, however clear the English is. So the file crosses as a pair: your English paper, or a fresh copy of it, and a Tajik text repeating every line, date and seal without shortening anything on the way.
Tajik in Cyrillic, and the care names need
A certified translation into Tajik in Wolverhampton is set in the Cyrillic alphabet from start to finish. Patronymic endings are the delicate part, because a name recorded one way on a Soviet-era paper and another way on a British passport can look like two people. Both forms go on the page, with the passport version leading and the older one following.
Who signs, and what the signature covers
The wording is a certified translation accepted by UK authorities, UKVI and the GRO among them, signed by an ITI/CIOL-qualified certified translator. That page lists the pages covered, names both languages and states that nothing was added or dropped. It stays attached to the Tajik text, and it is the piece an office reads before anything else.
Per-page cost and the delivery window
A certified translation for Tajikistan costs roughly £25 / page of source, delivered in 2–3 business days or in 24 hours where a date is already fixed. Family and inheritance files usually hold several thin records at once, so putting the whole set into a single order keeps the count accurate and avoids a second small job later.
Fresh UK copies, and what Dushanbe checks
Where a UK birth, marriage or death record is involved, Wolverhampton Register Office at Civic Centre, St Peter's Square, Wolverhampton WV1 1RU issues new certified copies. Letting that copy travel means the record you already hold never has to move. The office issues records; translating them and certifying a Tajik text lie outside what it does.
In Dushanbe a clerk reads the signed page, counts the sheets against it and then compares names with a passport. An official Tajik translation in Wolverhampton is delayed most often by a reverse side that was never scanned, since a stamp on the back is exactly where an older record carries its endorsement.