The following process I followed with my agent in Vital Certificates about now 2 and a half year ago. I hope it helps and you can contact the agency to inquire further as the rules might have changed now. but my certificate was attested as per the following procedure. Contact Vital Certificate & they are very professional and cooperative. when I inquired about attestation, they replied to me the following:
The attestation process for Saudi Arabia is as follows, you will need to produce supporting documentation as well as your certificate which will all be presented to the Saudi Cultural Bureau. The Saudi Cultural Bureau will then contact the issuing body for your certificate to validate it. Once a satisfactory reply has been received the Saudi Cultural Bureau will produce a stamped copy of your certificate. The stamped copy will then be sent to us and we will, in turn, pass it to the Saudi Arabian Embassy to be stamped and this completes the attestation.
The usual timescale for the whole process is quite long, there is no set time but a minimum of 8-10 weeks is standard. Once we have received your attested copy certificate from the embassy we will courier it to you worldwide using UPS or via Royal Mail Special Delivery if you would like it to be delivered to a UK address. The following are the requirements to support document attestation for Saudi Arabia:
1-Covering letter addressed to The Royal Embassy of Saudi Arabia, Cultural Bureau in UK, 630 Chiswick High Road, London W4 5RY requesting the attestation of your certificate, stating the reason why and your full address, contact numbers, and email.
2-Original Letter from your employer in Saudi Arabia, addressed to (Saudi Arabian Cultural Attaché) stating the reason (attested from Ministry of Foreign Affairs in Saudi Arabia for private sector employers).
3-Copy of your job offer from your present employer.
4-Copy of the photo page of your passport.
5-A signed consent letter addressed to the Records Office/Registry of the issuing body of your certificate (e.g. university, Royal College) giving consent under the Data Protection Act to the Saudi Arabian Cultural Bureau to authenticate your qualification. Please sign and print your name at the bottom of the letter.
I have posted above the followed procedure. I was in touch with ACCA to send UKSACB proof of my certificate. Although I was off the register in ACCA, so I had to pay ACCA to let them send an email to UKSACB to confirm that I completed my ACCA. Once ACCA had sent confirmation of my certification and I requested them to include me in CC, the further process was still long as we had to upload documents in UKSACB website and every time there was an error and the pupil there in the UK in UKSACB were not really helpful unless you contact them on daily basis. but Vital Certificate did a lot for me and I am really grateful that they received a certificate on my behalf there & then after making sure all the stamps are there, they couriered me.