Before sending an SMS campaign, check the actual recipients against the people who should no longer receive marketing. This comparison is usually called list washing. It is useful even when a business already has an unsubscribe process, because different teams, spreadsheets and sending platforms can otherwise carry different versions of a contact list.

A wash is a check at a particular time. It does not establish consent, prove that a number is deliverable or certify that an entire campaign complies with the law. The business remains responsible for its sending decisions. The Australian Government's guidance on commercial messages sets out the separate requirements for permission, identification and unsubscribe handling.

Start with the intended campaign audience

Export the recipients you actually intend to contact, rather than an old master spreadsheet. Use one row per recipient reference, a phone column and a stable external ID from your own system. A practical example is a customer record ID such as CUST-1042; avoid putting the phone number itself into the ID field.

Keep the country information clear. An Australian number written locally and the same number written with its international country code should be recognised as the same destination after normalisation. Preserve leading zeros when working in spreadsheets so that editing does not change a number before it reaches the wash.

Bring existing opt-outs with you

Import existing suppressions before treating a new tool as your working unsubscribe record. A change of platform should not lose requests received by reply, phone, email, a previous gateway or a staff member.

In 0TXT, importing pre-existing suppressions does not create a new usage charge. The shared register adds another matching source; it does not replace the opt-outs your business already knows about. Keep the original request evidence where you need it in your own records.

Run the wash and inspect every result

An approved business can upload its CSV to 0TXT. Each wash compares the rows against the active voluntary register and the business's existing suppressions.

  • SUPPRESS means do not include that recipient in the marketing send.
  • NO_0TXT_MATCH means no applicable record was found. It is not permission to send.
  • An invalid result needs correction and another check. Do not treat a parsing failure as a clear result.

Use your external IDs to apply the decisions back to the correct records. If one customer has several references in different systems, confirm that the suppression reaches each relevant marketing path. A clean-looking spreadsheet is of little use if an older campaign queue still contains the same recipient.

Apply the result before releasing the campaign

The sending platform is where the final exclusion must take effect. Download the result, update that platform's suppression controls and confirm the final recipient count before sending. Keep the wash time, campaign reference and the person who applied the result with your operational record.

An acknowledgement in a dashboard can show that someone reported an action. It is not independent evidence that an external gateway was updated. For a new workflow, test a number you control and check the sender's actual queue as well as the 0TXT result.

If a campaign is delayed or its audience changes, repeat the wash. Someone can register or unsubscribe after the original file was produced. Build that repeat check into your campaign procedure rather than relying on people to remember an exception.

Decide whether to retain contact mappings

0TXT supports one-off washing and an option to retain mappings for continuing matching. With retained matching, a new verified registration can create a suppression for a matching retained contact at an active participating business.

Retaining data is an operational choice with privacy consequences. Only retain mappings you need, protect access and make the appropriate disclosures. One-off files without retained mappings must be washed again for later sends. Neither option gives you access to the master register or another business's contacts.

Keep unsubscribe links and monitoring in the same procedure

0TXT's link-generation process also checks the register and existing suppressions. A matching row returns a suppression decision instead of a new link. For other recipients, the business can include the six-character link in its SMS and monitor subsequent requests.

The current pilot uses CSV exports for applying results. The business must check new requests and update its own sending system; a summary file alone does not complete that action. Set a named owner and a deputy before the first campaign.

To try the workflow, apply for a business account. Start with a controlled list and your existing suppressions, complete one wash and document how the result reaches your SMS platform. That working process is the foundation for adding an API later.