Yes that would work but they are using a buyer code, a seller code and a number and they are telling me that it is repeating. I'm not totally sure how it could and/or I suggested 1- buyer, 4 - number, 1- sp and 7th number be a A-Z if the number is the same . They are saying that can't work. I really just threw it out there in case someone else had a different solution.
Thanks @JeffSchwenk and @BethBowers