Vincentd

I'm Belgian. I work in Scotland since June 2021 ( full time) but I'm still a Belgian resident ( I commute between Belgium and Scotland). I have a UK contract in a UK company. I pay national insurance contributions in UK and I have a NHS number. So far , so good. I'm insured in UK and I can benefit from NHS services. As I still live in Belgium, I need health services as well. I know that there is a mutual agreement between both countries ( UK and Belgium) : I pay contributions in UK and I should be covered in both countries. Belgian Insurance company ( called "mutuelle" in French) is asking me information about the institution to which I'm insured (NHS in this case). I gave them my personal NHS number but it's not enough .. They want to get the "identification number of the institution", NHS in this case. I have no clue where I can find that number . They told me that they need that number to enable a wire transfer request. This information is part of the information to be filled in the E104 form which is used between UK and EU countries. Can someone help me ! Thanks a lot . Vincent