One job fixes the language
Papers used in Turkmenistan have to be readable in Turkmen, so a certified translation into Turkmen in Leeds is the piece of work you are buying. The writing is done once, from your source sheet, and the wording does not shift afterwards. What can change is how many signed copies of that wording exist. That is a separate decision, and people leave it far too late.
Who signs, and what the signature claims
You do not need a sworn Turkmen translator in Leeds for this: an oath taken in front of a court is not part of the route. Instead an ITI/CIOL-qualified certified translator writes the text, then signs and dates a statement of accuracy naming themselves. That statement is a narrow, checkable claim about words, made by someone whose qualification can be looked up.
How many signed sets to order
Work out how many places the paper is going before you order, not after. Each office that opens a file tends to keep its own copy, so two places to lodge it means two signed sets. The rate is worked out per page, at about £25, so the size of any one set is easy to work out in advance. An official Turkmen translation in Leeds is far easier to plan once you have counted both the pages and the places.
How fast a set comes back
A certified translation for Turkmenistan runs 2–3 business days on the standard clock and 24 hours on the express one. Those timings cover the writing and the signing, not the getting of the source record. Where a civil record is involved, Leeds Register Office at 2 Great George Street, Leeds LS2 8BA issues a fresh certified copy, and that request keeps its own pace entirely.
What the signed sheet settles
A certified translation in Leeds for Turkmenistan settles the language question: a Turkmen text exists, and a named translator has put a qualification behind it. It leaves your source record untouched, with its own wording and its own issuing office. Treat the two as a pair that travels together, and keep one spare signed set back for the file nobody warned you about.