A name arrives as a sound, not as a word
Saudi Arabia works in Arabic, so an English record needs an Arabic text beside it before an office there can use the contents. Most of that work is ordinary. Names are the part that is not, because a name has no meaning to carry across. It has a sound, and writing a sound in another script always involves a judgement that could reasonably have gone another way.
Take a surname with a vowel that sits between two Arabic ones, or a run of consonants that Arabic does not string together. Two competent translators may write it differently and both be right. That is tolerable on a single sheet and quietly destructive across a file, because a reader comparing your documents sees two spellings and has no way to know they belong to one person.
Decide once, then never vary
The remedy is unglamorous and effective: fix the spelling before the first Arabic line is written, and apply it without exception. A certified translation into Arabic in Nottingham that covers several records at once has an advantage here, since one translator sees the whole set and any drift is caught inside the job rather than discovered afterwards by somebody with the power to refuse it.
Where an Arabic spelling of your name already exists on something official, that spelling wins. It does not matter whether another rendering would have been more elegant. The purpose of the Arabic is to let a reader tie your papers to each other, and consistency with what already exists serves that purpose better than any improvement could.
Getting the sources lined up first
All of this argues for assembling the file before commissioning anything. An official Arabic translation in Nottingham built from a complete set is straightforward; the same work done in three instalments over as many months invites exactly the inconsistency the process is trying to avoid, and each instalment costs the same per page either way.
Where a record is a civil one registered in this city and the sheet you own is faded or was issued in an older format, a better source is easy to line up. Nottingham Register Office issues a fresh certified copy of a birth, marriage or death entry from The Council House, Old Market Square, Nottingham NG1 2DT, so a clean sheet can be used while the original you hold stays at home.