W9 Vendor Check

Given an invoice and a vendor record source (a spreadsheet, CSV, or text export with vendor name, contact, and a W9-on-file flag or date), this skill reports whether the vendor is known and whether a W9 is on file, citing the record it read. Vendor matching is conservative: it scans the whole record source first, and anything ambiguous or near-duplicate is surfaced for a human to pick, never auto-resolved and never drafted around. Conflicting W9 flags or dates across rows resolve to 'unknown,' and an ambiguous or missing field is always treated as NOT on file, never assumed compliant. When a W9 is missing, ambiguous, or the vendor isn't found at all, it drafts a ready-to-send vendor request: greeting, why they're being asked, a link to the blank IRS W9, instructions to return the completed form through the organization's own secure channel (or a note that no such channel is configured and a human needs to specify one), and a closing. It is a draft only; the skill never sends anything, and a human sends it. It never ingests, echoes, stores, or logs the actual contents of any W9 (TINs, SSNs, EINs), and it only reports vendor record fields by name and location, never by pasting the cell's contents. It's an administrative check, not tax or legal advice: it reports what the record source says and does not determine 1099, exemption, or withholding requirements.