When adding an IOSS #, the system masks the # you add, making it difficult to verify at the point of applying it to an order. The workaround is to add the same IOSS # to the nickname of the entry. There is no reason I can think of to mark that # from our orders. We added those manually to the system, and we also have total control over what is added. Additionally, it is not consistent with VAT for all countries.
Could you remove the masking of that IOSS?
Great Brick Lab

