Virginia supply offers their customers trade credit with terms 2/15, net 30. this implies that:

This implies that 2%/15 net 30 is a method of giving cash discounts on purchases. What this means is that if the bill is paid within 15 days, there is a 2% discount. Or else, the total amount is payable within 30 days. For instance, if "$1000 2/15 net 30" is printed on a bill, the buyer can take a 2% discount ($1000 x. 02 = $20) and make a payment of $980 within 15 days or pay the whole $1000 in 30 days.