transaction-processing

Transaction Processing

Purpose

Every financial transaction that hits the business — invoices received, expense reports, credit card charges, reimbursements — must be categorized, deduplicated, and flagged for anomalies before it reaches the general ledger. This skill ensures every dollar in and out is accounted for, properly categorized, and ready for posting, reducing bookkeeping errors and providing clean financial data for reporting.

When to Use

• "Process these transactions / receipts / invoices"
• "Categorize these expenses"
• "Enter these into the books"
• Upload of receipt images, CSV exports from bank/Stripe/QuickBooks, or raw transaction lists.
• "Reconcile and categorize this month's transactions"

Inputs Required

You must gather or receive:

1. Transaction source data — CSV export, bank feed, API dump, or manual list. Must include: date, amount, counterparty, description.
2. Chart of accounts — if not already known, load via ledger-management skill.
3. Previous period categorization — optional, for consistency checking.

Quick Reference

Concept	What It Does	Why It Matters
Auto-categorization	Maps transaction descriptions to COA categories using rules	Ensures every transaction has a home without manual effort
Deduplication	Scans for duplicate amounts/vendor/date combinations	Prevents double-counting, the most common bookkeeping error
Anomaly detection	Flags outlier amounts, missing fields, round numbers	Catches errors and potential fraud before ledger posting
Confidence scoring	HIGH / MEDIUM / LOW per categorization	Surfaces items that need human review
Multi-currency handling	Records original + USD-equivalent	Required for accurate P&L and cash reporting

Procedure

1. Parse the transaction file: detect format (CSV, JSON, PDF table). Extract: date, amount, counterparty, description, payment method.
2. Deduplicate: Check for duplicates against the existing transaction log. Flag any transaction that already appears.
3. Auto-categorize each transaction using these rules:
   • Software/subscriptions → Software & Subscriptions
   • Payroll/contractors → Payroll & Contractors
   • Rent/office → Facilities
   • Marketing/ads → Marketing
   • Travel/meals → Travel & Entertainment
   • Legal/professional services → Professional Services
   • Loan payments/interest → Debt Service
   • Revenue from customers → Revenue
   • Investments/grants → Other Income
   • Everything else → assign best-guess category and flag for review.
4. Flag anomalies:
   • Duplicate amounts to the same vendor in the same week.
   • Transactions over an outlier threshold (3x the median of the same category).
   • Round numbers that look like estimates rather than actuals.
   • Missing counterparty or description.
5. Prepare the output — a categorized transaction log.
6. (Optional) Post to ledger — hand off to ledger-management.