Payments for reporting purposes take on a multitude of forms and it is quite common to aggregate payments to reach reporting thresholds (watch your thresholds carefully - they are easier to reach than is often expected). Just because a payment is made by pettycash does not make it any different from one by check, p-card, wire transfer, etc... Just make sure that when you are tallying payments made to a particular vendor that you do not duplicate or omit any payments when aggregating amounts, you do not want to over- or underreport.