No, that is not necessary. Take care to activate the voucher in good time though. To do this you must apply for at least 1 trademark or design registration within 2 months of the date the voucher is granted, pay for it and request the refund. That registration can be a Benelux trademark or design (with BOIP), but it can also be a European Union trademark or a registered Community design (EU), a trademark or design registration with one of the EU Member States or a trademark or design registration with WIPO.
Once your voucher has been activated, you still have 6 months to apply for more trademarks and designs and to request refunds.