Resetting data

Exact method will depend on workbook structure and what record you will keep, how often vouchers are issued by each user etc.

But, I'd likely keep a table in hidden sheet, where user name and voucher count is tracked and incremented.

For an example use Environ("UserName") to verify who's logged in and issuing voucher. And increment corresponding value.

Edit: I'd also add Event code on Workbook_BeforeClose to auto save workbook. Or add code to save when voucher is issued.