Cowork Expense Audit Skill for Claude

Cowork Expense Audit

Process an expense folder the way a careful controller does: reconcile receipts against statements, categorize consistently, and separate what is provably documented from what is missing. Input is a directory of receipts (PDF, images), card/bank statements, and any expense exports (.csv/.xlsx). Never invent an amount -- every number in the output traces to a source file.

Workflow

• Inventory. Catalog every file: receipts, statements, exports, and unclassifiable items. Note date ranges covered. If statements and receipts cover different periods, say so up front.
• Extract transactions. Build a master ledger from the statements/exports: date, merchant, amount, currency. From each receipt: merchant, date, total, tax, payment method, line items when legible.
• Reconcile. Match receipts to statement lines (exact amount+date first, then fuzzy within 3 days and small tip/FX variance). Output three lists: matched, statement lines with no receipt, receipts with no statement line.
• Categorize every transaction (meals, travel, software, equipment, client entertainment, etc.). Use the company's category list if provided; otherwise propose one and apply it consistently. Tag anything client-billable separately.
• Flag. Apply the policy if provided; otherwise apply defaults and label them as defaults: duplicate charges, weekend/holiday spend on business cards, round-number amounts, per-transaction limits exceeded, subscriptions appearing monthly with no owner, personal-looking merchants, and split transactions that dodge an approval threshold.
• Report. Write expense-report.xlsx-ready CSV (or .xlsx if the xlsx skill is available) with the full categorized ledger, plus audit-findings.md: totals by category, reconciliation gaps, flagged items each with severity and the specific source file cited, and a missing-documentation list to chase.

Rules

• Never fabricate or estimate amounts. An unreadable receipt is logged as unreadable, not guessed.
• Flags are questions, not accusations. Write "no receipt located for..." not "unauthorized spend."
• Keep personal card statements strictly scoped: extract only lines the user identifies as business expenses; do not summarize personal activity.
• Show your matching: every matched pair cites both source files; every unmatched item says what was searched.
• Currency: preserve the original currency and note the statement's settled amount; never silently convert.
• If more than 20% of transactions lack receipts, lead the findings memo with that fact -- it is the finding.

Scheduled Mode

As a monthly Cowork scheduled task pointed at a receipts inbox folder: process new files, append to the running ledger, and deliver the month's report and findings without re-litigating prior months.

Quick Commands

• "Audit [folder]" -- full workflow
• "Reconcile only" -- steps 1-3, the matching report
• "What's missing?" -- unmatched statement lines and the chase list
• "Billable pull" -- client-billable transactions grouped by client