Any voucher that is used for the same service or services will be lumped into the same available pool for clients to use. On our end, when checking out we only see the total number available with no distinction between them. This can create a problem because we allow the sharing of voucher packages but not membership vouchers. A client might buy a package with the intent of sharing but those vouchers could be used first through individual appointments. When it came time to share it would look like they didn't have any to share because they'd only have membership ones left.