Vendor bills — supplier invoice triage with Claude Cowork

TL;DR. Process the inbox of supplier invoices — extract data, code to GL, match to POs, prep a payment batch for approval. Around 5 hours per week saved for an AP clerk handling 80+ bills per period. The PO-matching tolerance is the single biggest dial.

Job to be done#

Process the inbox of supplier invoices: extract data, code to the GL, match to POs, and prepare a payment batch ready for approval.

Who runs it#

AP clerk or finance-ops associate.

Inputs (inbox/)#

• Supplier invoices (PDF, image, sometimes Excel) in /inbox/vendor-bills-[period]/
• Chart-of-accounts mapping
• Open PO list export
• Vendor master file

Outputs (output/)#

• vendor-bills-[period].xlsx — one row per invoice with vendor, invoice number, date, due date, amount, currency, GL code, PO match status
• A for-approval/ subfolder of invoices ready to be paid
• An exceptions/ subfolder with mismatches: no PO, amount drift, missing data

Prompt seed#

Read every PDF/image in /inbox/vendor-bills-[period].
Extract: vendor, invoice number, invoice date, due date, total, currency, line items.
Match against /inbox/open-pos.xlsx by vendor + amount tolerance (5%).
Apply GL code from /inbox/coa-mapping.xlsx using vendor + line description rules.
Output to /output/vendor-bills-[period].xlsx.
Move the source files to /output/for-approval or /output/exceptions accordingly.

Quality bar#

• Vendor name normalised (Acme Ltd vs ACME Limited vs Acme).
• Amount matched within tolerance, never silently corrected.
• GL coding always cites the rule that produced it.
• Common trip-up: invoice numbers with leading zeros. Preserve as text.

Time saved (typical)#

About 5 hours per week for an AP clerk handling 80+ bills per period.

Upgrade path#

• Add a connector to your accounting system to post directly, instead of producing an Excel for someone else to upload.
• Convert to a vendor-bill-triage skill once stable.

Tinkso's take#

PO-matching tolerance is the single biggest dial. Too tight and half the inbox lands in exceptions; too loose and you pay overcharges. Start at 3–5% and adjust monthly based on the exception rate. Track the exception rate in a sheet that the AP clerk owns; it is the most useful metric you will track in this workflow.