Yes, it is possible to on-board (a) MAH(s) separately though there is already a registered OBP. A MAH or MAHs can on-board separately, registering and on-boarding as or under a separate OBP. However, EMVO will apply the on-boarding fee depending on the amount of MAHs per OBP. Moreover, please note that in general one MAH can only be associated to one OBP. Only in the case of an hybrid company (one entity with both company types), a double application of an MAH to two separate OBPs is possible.
Please note that regarding the company type a separate on-boarding of MAHs under a separate OBP also might be necessary as an OBP can either only represent Original Pack Manufacturers or only Parallel Distributors.