Keep evidence of what you sent, not just a tracking number

The customer says it never saw the attachment
Suppose you have a postage receipt for a demand, but the saved folder contains several drafts and different invoice attachments. The customer says the amount was unexplained. The tracking record does not tell you which document set was actually sent.
Keep a complete sent pack. It should connect the final letter, supporting documents, recipient details and delivery record in one place.
Check the recipient details before dispatch
Use the contracting party's details and an appropriate contact route, with advice where identity or formal requirements are uncertain. A site address, trading name and company registered office may serve different purposes.
Do not send a company demand to an individual's family members merely to create pressure. If responsibility for the debt is disputed, resolve the identity question with the documents and suitable advice.
Save the exact contents
Retain the signed and dated version, the account reconciliation and every attachment listed in the letter. Give the set a clear reference. If sending electronically, keep the outgoing message with the actual attachments rather than just a draft in the email system.
business.gov.au recommends keeping original documents and a copy of the signed demand. Linking those copies to the sending record makes that retained history easier to follow.
Record the delivery outcome accurately
Keep the available postal or electronic delivery information and any returned-mail or error notice. Record the date you became aware of a failure. Do not describe an email as read solely because it appears in your Sent folder.
Equally, a tracking update does not by itself settle every legal service question. Ask a lawyer about the requirements for any formal document; ordinary correspondence and statutory or court processes should not be treated as interchangeable.
Respond sensibly to a delivery problem
Check the address and contact information before repeating the same failed method. Confirm a suitable route through an established business contact where appropriate. Preserve the failed attempt as part of the history.
If a legal deadline is involved, obtain advice promptly. Do not assume that resending an ordinary letter restarts a legal period or fixes a problem with a different formal notice.
Make the file ready for the next adviser
Provide the sent pack and the actual delivery history if the account needs escalation. Identify uncertainty honestly: for example, delivery recorded but contents disputed, or electronic transmission failed.
Use Report a Debt below if CRP is helping with the account. A clear dispatch history can reduce questions about what happened, while leaving the validity and consequences of formal service to the appropriate professional assessment.