Originally Posted by Scoob72

Tokyoite • JALPak - many thanks for the further comments.

I was going to contact BA directly, as suggested, but then an obscure recollection made me think of Royal Jordanian and their website: I entered my JAL flight info into their Manage My Booking and I was able to add my API info there successfully. I then received an automated email from RJ confirming these changes. Although, subsequently, I've not been able to see these API updates within JAL or BA's systems in terms of my booking, I hope that this might have put paid to the issue. (Saying that, I might call BA in due course anyway just to verify that they can see this updated API info.)

Again, thank you for all your help.