Deleting an opted-out contact from a campaign file does not prevent it appearing in the next import. The durable control is an exclusion that every release path checks. This guide explains how to preserve that control without turning the suppression store into another marketing dataset.

Define what the request covers

Record the person or contact point, sender, channel, scope and date of the request. Keep the original wording where necessary to resolve ambiguity. A narrowly described newsletter withdrawal may have a different scope from an objection to all direct marketing.

The ICO’s preference guidance explains why keeping minimal suppression information can prevent renewed contact after an objection. Suppression is distinct from retaining a complete profile for marketing. Keep only what is needed to recognize and respect the preference, and do not use that store as an audience source.

Choose matching rules deliberately

Identifier	Useful control	Risk to review
Email	Match the contact point using documented normalization.	Over-aggressive rewriting may merge different addresses.
Telephone	Use a reviewed country-aware representation.	Guessing a missing country code can exclude or contact the wrong person.
Person or account	Use a stable identifier where a broader request requires it.	A name alone is usually too ambiguous.
Historical reference	Preserve necessary links between previous and corrected identifiers.	An updated record may otherwise bypass the earlier exclusion.

Do not assume a hashed identifier is anonymous. It may still identify or match a person and needs suitable access and retention controls. Also document which normalization occurs before hashing, or equivalent imports may fail to match.

Put checks at more than one boundary

Screen incoming files before they enter active campaign lists. Check again at final export or dispatch because a withdrawal can arrive after import. Supplier refreshes, CRM syncs and manual uploads must use the same current preference source.

Keep unmatched and uncertain cases in a review queue. Do not reactivate a record because a newer file labels it “active” without evidence that the relevant preference has lawfully changed. Imported status and a new source date do not erase an earlier objection.

Use a small controlled acceptance test

1. Create a test contact controlled by your team.
2. Apply an opt-out with a clearly recorded scope.
3. Import the same contact through the normal supplier route.
4. Repeat through a manual upload and another integration if used.
5. Confirm that the final campaign output excludes the relevant contact.
6. Review what happens when a withdrawal arrives after a campaign is queued.

Measure failures in the process, not only the number of suppressed rows. A connector that silently skips the exclusion is more important than a large suppression total.

Handle deletion and suppression together

A person can ask for both removal and no further marketing. Route the request through the applicable privacy process and explain any minimal exclusion retained for that purpose. Avoid deleting the only matching key without considering how the preference will survive a later refresh.

Document access, review and disposal decisions for the suppression store. Staff who need only an eligible campaign file should not automatically receive the underlying request evidence.

Read the permission records checklist and SMS withdrawal test. For a request about your information held by Latest Mailing Database, use Opt Out or our Privacy Policy.