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Check the file shape before interpreting its content

Last materially reviewed 2026-09-27

Quick answerValidate headers, row counts and field boundaries before blaming a verifier for an unusable return.
What to know

Keep the original

Work from a copy of the export. Record its filename, creation time, column names and row count. Spreadsheet applications may reinterpret fields when opening or saving a file; a visually tidy sheet does not establish that the vendor received the intended structure.

What to know

Inspect the contract

Use the current format requirements for your chosen upload or integration. Confirm the address column, supported file type and any identifier requirements. Do not treat a generic CSV label as a guarantee that every delimiter, encoding or embedded line break is accepted.

What to know

A bounded rehearsal

Use a synthetic fixture containing an empty row, a quoted field and a deliberately reordered identifier. Check the transformation locally without sending live data. If a parser changes the number of records or splits one field into several columns, fix that structural issue before interpreting technical result labels.

What to know

Put it into practice

Create a tiny local fixture that includes a blank field, a quoted comma, an embedded line break where the format permits it, and a stable identifier. Use fictional values rather than real addresses. Pass it through the same export and import transformations you intend to use, then compare the parsed fields and record count. This exposes file-shape assumptions without sending private data to a service. Keep the original fixture and expected result as part of the mapping record. If a spreadsheet application changes a value during opening or saving, investigate its import settings instead of treating the displayed grid as authoritative. The goal is a reproducible transformation, not a visually attractive sheet. Verify the vendor's current accepted format separately; a locally valid CSV is not proof that a particular upload route supports it or preserves every optional column.

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Next: Preserve row identity across the result file

Use an explicit reconciliation key; spreadsheet position alone is a fragile identity system.

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Related guides

Preserve row identity across the result fileUse an explicit reconciliation key; spreadsheet position alone is a fragile identity system.Use a preflight checklist that can say noA batch is ready only when input, authority, destination and return ownership are clear.Investigate an unexpected result without compounding itPause dependent changes, preserve the evidence and isolate the failing stage.

Sources used for this page

These records support the facts and comparisons above. Merchant-controlled records are labelled so you can separate product claims from independent evidence.

  1. Bouncer API introduction — Merchant documentation · docs.usebouncer.com · Merchant-controlled · checked 2026-09-27
  2. Bouncer integrations — Merchant documentation · usebouncer.com · Merchant-controlled · checked 2026-09-27