Supplier Statement Reconciliation Methodology

SupplierRecon uses explicit, deterministic rules to compare one supplier statement with one AP ledger export. It separates narrow Exact matches from review candidates, unmatched records and data warnings, then preserves source traceability and control totals in an Excel workpaper.

Method version: engine 2.0.0 · Page reviewed: 2026-08-22

Open the local reconciliation tool

Supported inputs and processing boundary

One supplier statement and one AP ledger or open-item export.
CSV up to 25 MB and 200,000 parsed data rows; XLSX up to 10 MB and 50,000 parsed data rows.
No PDF, image, OCR, XLSM, ODS, macro, encrypted workbook or legacy Excel-container support.
Parsing, normalization, matching, review state and XLSX generation run in the browser. Transaction files are not sent to an application upload endpoint.
The active transaction session is held in memory and is cleared on refresh or tab close. Only mapping and format-rule templates are saved locally when the user explicitly requests it.

Field mapping

The user chooses the worksheet and actual header row for each source. Reference and either amount or paired debit/credit mappings are required. Date, currency, supplier, transaction type and description are available mappings. Multi-supplier AP scope requires an AP supplier mapping.

Normalization rules

Field	Current behavior	Warning or boundary
Reference	Convert to text, apply Unicode NFKC, trim and uppercase. Spaces and hyphens are retained in the match value.	Empty values and numeric long identifiers at precision risk are blocking. Scientific notation is blocking.
Amount	Remove confirmed grouping characters, interpret decimal separator, parentheses and trailing minus, apply sign direction, and round half-up to integer minor units.	Unparseable or empty amounts are blocking. Debit and credit columns can be combined in either confirmed direction.
Date	Interpret MM/DD/YYYY, DD/MM/YYYY or YYYY-MM-DD, plus numeric Excel serial days, as a timezone-independent day.	Missing, invalid and ambiguous dates create non-blocking warnings. Missing dates cannot contribute positive date-window evidence.
Currency	Trim and uppercase the mapped value or use the confirmed three-letter default.	Currency is part of every deterministic match boundary; control totals never combine currencies.
Supplier	Apply Unicode NFKC, trim, collapse internal whitespace and uppercase.	Multi-supplier AP rows with missing or out-of-scope suppliers are blocked from matching.
Source conditions	Retain hidden rows when configured and use cached formula results from XLSX.	Hidden rows, formula results and duplicate raw rows remain visible as warnings; they are not silently removed.

Exact match definition

An Exact match is only EXACT_UNIQUE_1_1. The normalized reference, integer minor-unit amount and currency form a composite key that must occur exactly once in the statement and exactly once in the AP ledger. Supplier scope must be explicitly confirmed and compatible. If both dates are present, their distance must be within the confirmed date window. If either date is missing, the record carries a warning but the missing date alone does not block an otherwise unique exact key.

Exact does not mean approved

The classification says only that the loaded records satisfy the current deterministic rule. It does not establish invoice validity, correct accounting, payment approval, fraud absence, source completeness or audited supplier balance confirmation.

Review candidate definitions

Result code	How it is produced	Automatic status
`RULE_UNIQUE_1_1`	Same normalized reference and currency, supplier safeguard passes, both dates are inside the window, amount difference is within the configured tolerance, and neither row has competing claims.	Needs review
`SUGGESTED_1_N`	One statement row has exactly one AP combination whose amounts sum exactly. Candidates must share supplier and currency and sit inside the date window. The current search considers at most eight nearby AP rows and groups of two to five rows.	Needs review
`AMBIGUOUS_MULTIPLE_CANDIDATES`	More than one AP combination produces the exact statement amount. The engine records alternatives and does not select randomly.	Needs review
`SUGGESTED_FUZZY`	Equal amount and currency, supplier safeguard and date window pass, then reference or description token/prefix similarity scores at least 0.35. Similarity ranks up to five candidates.	Needs review

The engine currently proposes one statement row to many AP rows. It does not automatically build many-statement-to-one-AP groups. A reviewer must investigate that pattern outside the automatic grouping result. Every accepted suggestion remains distinguishable from an Exact match.

Supplier, date and currency safeguards

Supplier scope: exact matching is disabled until single- or multi-supplier scope and a supplier value are confirmed. Multi-supplier AP rows outside that normalized value are excluded with warnings.
Date window: where both dates exist, an outside-window pair cannot be Exact and is classified for review. Grouped and fuzzy candidates require dates inside the window.
Currency: reference keys, amount candidates, grouped candidates and fuzzy candidates all require the same currency. There is no currency conversion.

Ten exception categories

Exception names are deterministic review labels. “Possible” categories deliberately avoid asserting an accounting fact.

Code and visible name	Trigger meaning	Suggested manual check
`STATEMENT_NOT_IN_AP` Statement record not found in AP	No eligible AP row was found under the confirmed rules.	Check period, supplier filter, reference and posting status.
`AP_NOT_IN_STATEMENT` AP record not found on statement	No eligible statement row was found under the confirmed rules.	Check statement timing and whether the item belongs to another period.
`AMOUNT_MISMATCH` Amount mismatch	The same normalized reference exists, but eligible amounts differ.	Check tax, freight, partial postings, credits and sign direction.
`DATE_OUTSIDE_WINDOW` Date outside window	Both dates exist and exceed the confirmed date window.	Confirm document date, posting date and cut-off.
`POSSIBLE_DUPLICATE` Possible duplicate record	Another source row has the same raw values; this is a possibility, not a conclusion.	Compare source identifiers and validate both postings.
`POSSIBLE_UNUSED_CREDIT` Possible unused credit	An unmatched negative AP amount may represent an unused credit.	Review the supplier credit balance and application history.
`ONE_TO_MANY_CANDIDATE` One-to-many candidate	One statement row has one AP combination with an equal amount.	Verify every component before accepting.
`MULTIPLE_CANDIDATE_CONFLICT` Multiple candidate groups conflict	More than one AP combination satisfies the deterministic amount criteria.	Select a group using source evidence or leave unmatched.
`DATA_PARSE_WARNING` Data parsing warning	At least one source value produced a parsing or source-condition warning.	Inspect the original file, worksheet, row and mapped value.
`SUPPLIER_SCOPE_WARNING` Supplier scope warning	Scope is unconfirmed, missing, conflicting or outside the run filter.	Confirm supplier scope and AP supplier mapping.

Control totals

For each source and currency, the workpaper reports input rows and amount, valid parsed rows, Exact rows and amount, manually accepted rows and amount, unmatched rows and amount, warning rows, excluded rows and amount, matched total and final classification difference. Export asserts:

valid parsed rows + excluded rows = input rows;
Exact rows + manually accepted rows + unmatched rows = valid parsed rows;
input total − matched total − unmatched total − excluded total = zero.

These invariants prove classification coverage of the loaded data. They do not prove that the source systems supplied a complete population or that the accounting entries are correct.

Source traceability and workpaper

Records retain source file name, worksheet, original row number, raw source columns, normalized fields, warnings, match group, result rule and version. Review decisions retain selected candidate rows, reason, note and timestamp. The eleven-sheet workpaper contains Summary, Rules & Parameters, Exact Matches, Reviewed Matches, Unmatched Statement, Unmatched AP Ledger, Data Warnings, Exceptions, Source A Reconciled, Source B Reconciled and Run Manifest.

The Run Manifest records SHA-256 input hashes, settings, engine version, result fingerprint, counts, source metadata, supplier scope and currency totals. It is reproducibility metadata, not a digital signature, identity attestation, approval record or tamper-proof proof.

Known limitations and required human review

Only two loaded tabular sources are compared; there is no ERP connection, document retrieval, OCR, PDF interpretation or bank/payment verification.
Reference normalization does not remove punctuation or infer invoice-number semantics.
Text similarity is a simple deterministic token/prefix score used only for candidate ranking.
There is no foreign-exchange conversion, tax logic, account coding, aging validation or supplier-balance confirmation.
File completeness, period cut-off, supplier identity, mappings, currencies, signs, credits, duplicates, candidate acceptance and final accounting treatment require human review.

Terminology

Exact match: A unique one-to-one result satisfying the configured deterministic exact rule.
Needs review: A candidate or ambiguity that the engine does not treat as a financial conclusion.
Unmatched: A valid loaded row not assigned to an Exact or candidate group.
Excluded: A loaded row blocked by parsing, precision, hidden-row or supplier-scope conditions.
Control total: A source-and-currency classification check over the loaded population.