The short answer
For business correspondence that needs a mailing record, compare the record provided by Certified Mail with the additional recipient-signature evidence available through Return Receipt. IRIS can quote and submit a reviewed Certified letter through its API, but a postal record does not establish that your notice satisfies a legal or contractual requirement.
Start with the record your team needs
An ordinary service confirmation and a time-sensitive contractual notice may have different requirements. Decide what your team needs to document before selecting a mailing option. A record of order creation, a postal delivery attempt, and a recipient’s signature are different forms of evidence.
USPS describes Certified Mail as providing proof of sending and information about delivery or an attempted delivery. Combining it with Return Receipt adds a record of the accepting person’s signature. Check the USPS service details for the distinction, and use the IRIS quote for the total cost of the supported online mailing.
Match the option to the intended correspondence
Use this comparison to frame an operational decision. It does not determine the mailing method required by a contract, agency, court, or statute. Confirm those requirements with the relevant authority before sending a notice that depends on them.
| Record or option | What to check |
|---|---|
| IRIS order ID | Identifies the mailing order in your account. |
| Certified Mail | Postal record of sending and delivery or attempt information. |
| Return Receipt with Certified Mail | Additional recipient-signature record. |
| Your retained final PDF | Documents the content your team approved for mailing. |
Set the letter options explicitly
IRIS uses certified and certified_return_receipt in the letter options object. Return Receipt requires Certified Mail. The fragment below illustrates those options only; a complete request also needs product, primaryDocumentId, sender, and recipient.
Certified letters are limited to six sheets: six single-sided or twelve double-sided pages. Register the actual PDF before quoting so the system can validate its page count. Obtain a new quote if you change print options or the document.
{
"color": false,
"double_sided": true,
"certified": true,
"certified_return_receipt": true
}Keep the content and order record together
Your application should retain the final PDF or an appropriate controlled reference to it, its document ID and fingerprint, the approved recipient, the reviewer, and the purpose. After submission, add the returned orderId and the current status as it becomes available.
Do not promise that a PDF of a signature receipt is returned by GET /v1/mailings/{id}; the current response exposes order status and available tracking fields. Confirm how your team will access the particular record it needs before depending on that artifact. Maintain your own appropriate record-retention process.
Handle timing and exceptions deliberately
A paid order is not a delivery confirmation, and a delivery attempt is not the same as successful delivery. Leave time for processing and postal transit. When correspondence carries a deadline, verify the required method, address, and timing independently of this general integration walkthrough.
Route returned mail, unclear status, and recipient-address corrections to a person. Do not automatically send a replacement merely because tracking is unavailable. Reconcile the existing order first and obtain approval for any new mailing intent.
Sources & further reading
Product details checked against the IRIS API contract when this article was published. Platform references can change; consult the linked documentation when implementing.
- IRIS API documentation and current limits
- IRIS OpenAPI contract
- USPS: Certified Mail and Return Receipt
Published by IRIS Postal Forms, operated by Great Lakes Computing Office LLC. Send a correction.