Open finance skill
Duplicate billing check
Which invoices may have been entered or billed twice?
Flag repeated invoice numbers and near-duplicate vendor, date, and amount combinations without deciding whether either entry is valid.
Inputs
- ✓Invoice list
- ✓Vendor names
- ✓Dates and amounts
Outputs
- ✓Exact duplicates
- ✓Possible duplicates
- ✓Review reasons
Checks performed
- ✓Repeated invoice number
- ✓Same vendor, date, and amount
- ✓Near-date duplicate pattern
Guided synthetic example
See the check from input to decision
Two invoices from the same vendor carry the same invoice number and amount.
This is the operating model we use at Level. The percentages are estimated shares of the work in a typical review. Actual effort varies with data quality, complexity, and the issue found.
Start with the source records
About 15% of work| Record | Vendor | Invoice | Date | Amount |
|---|---|---|---|---|
| AP-881 | Example Supply | EX-4402 | Jul 10 | $8,250 |
| AP-914 | Example Supply | EX-4402 | Jul 13 | $8,250 |
Run the deterministic check
About 20% of workFlag an exact invoice-number match, then compare vendor, amount, and nearby dates.
Surface the flagged result
About 10% of workNeeds review
Probable duplicate: same vendor, invoice number, and amount, entered three days apart.
Use recorded finance judgment to analyze possible reasons
About 25% of workAt Level, we record the review logic, known explanations, and questions our finance professionals use in this situation. AI applies that documented human judgment to organize the most plausible reasons, without pretending it knows which reason is true.
Possible reasons to investigate
One record may be a duplicate, but it could also be a correction or legitimate split posting.
Make the final human judgment
About 20% of workA Level finance professional validates the source evidence, challenges the AI-assisted analysis, and decides which explanation is supported.
Make the operating decision
About 10% of workOpen both source documents and confirm which record, if either, should be voided.
Use this system
Start with the example, then inspect the structure
- Download the invented input and expected output.
- Replace one field at a time with a safe test value.
- Compare the result with the expected structure.
- Have a finance professional review every exception before acting.
MCP preview
run_synthetic_example {"slug":"duplicate-billing"}Human review is part of the system
This check organizes evidence and surfaces exceptions. A person with finance domain expertise still needs to interpret the result, validate the source records, and discuss the operating decision.
Open source does not mean open client data. We publish reusable finance tools, checks, templates, and playbooks. Client records, workpapers, credentials, communications, and private configurations remain confidential.