can not add my iban accaunt

can you clarify exactly what the problem is so that a fellow partner might be able to help?

is the problem with your iban number not being accepted by the booking.com portal?

here is what the help says in case it might be easier:

For questions about invoicing or other finance-related issues, feel free to contact our Finance Department. Telephone : *(Office hours Monday-Friday 9 to 17:00)

*edit ... the telephone number gets taken off by autoadmin but you can easily find it form the help.