Duplicate invoice check

What does the duplicate invoice check produce?

Find repeated supplier and invoice numbers, conflicting invoice details, and equal supplier, amount, currency and date candidates. Keep every source row for review.

The working area above runs the supported validator in the browser. It keeps the result inspectable and preserves every unresolved item for responsible review.

What do you need before you start?

• Use one invoice header per row. Do not supply invoice lines, installment payments or multiple legal entities with unqualified supplier IDs. Record the source period, snapshot and exclusions.
• Use UTF-8 CSV, rectangular text dataset JSON or one-sheet values-only XLSX starting at A1. Limits are 10 MB, 5000 rows, 50 columns, 100000 cells and 5000000 parsed characters. Formulas, macros and additional sheets are rejected.
• Use text identifiers, currencies and YYYY-MM-DD dates. XLSX amount cells can use finite decimal numbers with at most 15 significant digits and six decimal places. Stored numeric values become decimal text. Displayed currency and rounding are ignored. Use text amounts when original decimal precision matters.

What information do you enter?

Prepare only the bounded inputs listed below for this validator.

• Record reference, Supplier, Invoice number, Invoice amount, Currency and Invoice date. Use the displayed aliases. Each required heading must occur exactly once.
• Population and snapshot basis. Choose exact invoice-number text or explicit ASCII case and separator comparison. Supplier and record references always match exact text.
• Signed decimal amounts with up to 15 integer digits and six decimal places. Uppercase three-letter currency labels and exact YYYY-MM-DD dates from 1900 through 2200.

What you can download

Every result must identify its supplied facts, assumptions and unresolved items.

Fictional invoice review (PDF). Editable review (DOCX). Complete fictional pack (ZIP). Fictional source dataset (JSON). Requires tailoring. Samples use the same finalized renderer. Keep real source and result files private.

How does the duplicate invoice check work?

1. 1
   Select your invoice export

   Preserve the original file. Inspect the required headings or try the fictional example. Each row represents one invoice header.

2. 2
   Freeze the population and comparison

   Record the snapshot and exclusions. Choose exact invoice text or the disclosed ASCII comparison. No supplier normalization occurs.

3. 3
   Inspect all candidates

   Every duplicate occurrence remains visible, including the first. Review conflicting dates, amounts and currencies. Equal supplier, amount, currency and date can flag different invoice numbers. Missing facts remain unresolved.

4. 4
   Keep sources and results

   Download complete JSON, CSV and exact original source free. Download the free seven-file finalized pack after reviewing every candidate.

Method and sources

Apply the steps above to the supported inputs. Use the listed source sections to review the rule basis, assumptions and limits.

• Vendor invoices overviewContext for invoice-number review and original invoice records. This tool uses its own disclosed comparison method, not Dynamics configuration. Vendor invoice headers, duplicate number controls and transaction currency.Microsoft. Reviewed 2026-10-06.
• Vendor invoice datesInvoice date is distinct from receipt, posting and due dates. The selected source must identify the intended date. Invoice dates and distinct posting or receipt dates.Microsoft. Reviewed 2026-10-06.

Common questions

What still needs review?

Candidates require original invoice and ledger review. Matching facts do not prove duplicate payment, fraud or recoverable loss. This tool does not delete invoices, approve or block payments, query a ledger, convert currency or authenticate documents.

Method revision 2026-10-06.duplicate-invoice.1.

Group exact supplier IDs with invoice numbers using the selected comparison. Every occurrence is retained, including the first. Original strings never change.

Separately group exact supplier IDs with equal signed decimal amounts, exact uppercase three-letter currency labels and valid YYYY-MM-DD invoice dates. This secondary comparison can flag different invoice numbers. It uses no date tolerance, currency conversion or fuzzy supplier matching.

Amounts support a minus sign, 1 through 15 integer digits and at most six decimal places. Leading zeros and trailing decimal zeros compare numerically using scaled integer arithmetic. No rounding, float arithmetic, commas, exponents or currency symbols. Negative and zero amounts remain review items, never inferred losses.

Currency labels require three uppercase ASCII letters. The tool does not infer currency or verify currency-code membership or minor units. Dates require exact YYYY-MM-DD from 1900 through 2200.

Duplicate record references and missing or unsupported values remain unresolved. Known supplier and invoice facts can still identify a candidate. Missing facts cannot establish a unique invoice.

Identifier groups report conflicting amounts, currencies or dates, including incomplete detail coverage. Group numbers follow first source occurrence. Source row numbers count the header as row 1.

The first earlier original remains available after replacement. Invalid replacements preserve the current source. Clear removes current and earlier local files. Keep local backups of your original files and downloaded results.

The interface shows the first 200 rows. PDF and DOCX summarize the first 100 rows and candidate groups. Excel and JSON retain complete source and group membership. CSV uses spreadsheet-safe escaping. PDF uses explicit Unicode escapes for unsupported characters.

Related working records

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