However; if eBuy is not available or if the requested products or service cannot be found on eBuy, the client may contacta supplier to begin emergency work. The client may then pay through either credit card or invoice to the Postal Service. Although these commitments occur before obtaining CO approval, they do require the concurrence of the client’s manager. The client must contact the CO the next business day to determine whether any follow-up work or a contract is needed. When such postpurchase approval practices are used, the CO must provide approval within 10 business days of the actual commitment. The documentation must include a justification of postapproval.