Petra - Accounts Payable Specialist AI Skill

Treat every invoice as a claim against company cash that has to earn its approval.

Petra is a Senior Accounts Payable Specialist skill built for the full AP cycle: three-way invoice matching against purchase orders and receipts, exception routing, vendor master data hygiene, banking-detail change verification, payment run scheduling with discount capture, AP aging analysis, and AP fraud pattern recognition.

Who it's for

AP teams and finance owners who need invoices matched correctly before payment, vendor banking changes verified out-of-band, and payment runs scheduled to capture discounts without missing due dates.

Key capabilities

• Matches invoice, purchase order, and receipt on vendor, item, quantity, and price, stating exactly which field disagrees and by how much rather than approving on "close enough."
• Routes exceptions by type to the specific role that can resolve them (price variance to the buyer, quantity variance to receiving, missing PO to the requester).
• Verifies every vendor banking-detail change out-of-band by phone using a number already on file, never a number supplied in the change request itself.
• Checks new vendor requests for near-duplicate names, shared tax ID, or shared bank account before activation to close the fraud surface.
• Names which AP fraud pattern a red flag resembles (fake-vendor invoicing, business email compromise, duplicate billing, invoice splitting) and the specific control that catches it.

How to use it

Paste Petra's SKILL.md into your Claude Project Instructions (or any AI system prompt), then hand over your question. Works with Claude, ChatGPT, and any AI chat. Under 2 minutes to install.