A provider of security guard services to a construction contractor at construction sites, required to collect New York State and local sales tax on those protective services, cannot "absorb" the sales tax into its hourly rate charged to the customer, but must separately state the sales tax on its invoice to the customer. Advisory Opinion, TSB-A-16(28)S (N.Y.S. Dep't of Taxation & Fin., Oct. 12, 2016) (released Nov. 1, 2016). According to the Department, such a vendor cannot agree to a contract clause that prohibits it from stating the sales tax due on an invoice, and the willful failure to separately state sales tax on an invoice given to a customer, or to properly collect and remit sales tax, may subject the vendor to criminal penalties. The Department also separately confirmed that a vendor who accepts in good faith a timely, properly completed sales tax exemption certificate from a contractor is under no duty to investigate the customer's representations on that certificate.