Practical guide

Decide what a duplicate means before removing it

Last materially reviewed 2026-09-27

Quick answerA duplicate technical address may still be linked to different business records; preserve the distinction.
What to know

Count two things

Count rows and distinct addresses separately where your authorised workflow permits. Two rows may represent the same address but different subscriptions, history or business relationships. Deduplicating a verification input is not the same operation as merging customer records.

What to know

Keep the return path

If you create one technical check for several source rows, retain a controlled mapping so the observation can be associated correctly without collapsing consent or exclusion differences. Never infer that all records sharing an address have identical permission.

What to know

Synthetic example

A fictional address appears once in a membership table and once in a volunteer table. One role is excluded from a particular campaign. A shared technical result must not overwrite that difference. Write the duplicate rule and expected return count before processing, then reconcile against that rule rather than an assumed one-row-per-person model.

What to know

Put it into practice

Document three distinct operations: removing repeated input addresses from a technical check, linking one observation back to several source records, and merging business records. The first does not authorise the third. In a fictional directory, two rows share a team inbox because they represent different committees. One committee's newsletter permission is current and the other relationship is archived. A single technical observation can be relevant to both without making the two relationships interchangeable. Preserve each row's identity and exclusions. If your process cannot express that distinction, do not collapse the rows merely to reduce a charge or simplify a spreadsheet. Record how duplicate inputs affect the expected result count so the reconciliation worksheet uses the correct denominator. A vendor's duplicate-charging policy is a pricing fact; it is not a complete data-governance rule for the organisation's records.

Continue when useful

Next: Preserve row identity across the result file

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

Open Preserve row identity across the result file →

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 pricing — Merchant documentation · usebouncer.com · Merchant-controlled · checked 2026-09-27