Certified mail is an add-on service offered by USPS for First Class mail that provides proof of mailing to the sender. With electronic USPS tracking, the sender is notified when the mailing was delivered or that a delivery attempt was made. An Electronic Return Receipt showing the recipient's signature is also available.
You send letters as Certified mail through the Lob API by passing the value certified in the “extra_service” parameter of the create letter request. You may similarly opt for an Electronic Return Receipt by passing certified_return_receipt in the “extra_service” parameter. Tracking events are viewable directly within the Lob Dashboard or via the API, similar to how they are for non-certified letters, and you can also subscribe to Webhook events for Certified letters. When you make a request for Certified mail you will immediately receive a carrier tracking number (retrievable via your Lob Dashboard), which can be used to track the mail via the carrier’s website - or you can choose to track the mail via the scan events within your Lob Dashboard. The resulting screen should appear something like this within your Lob Dashboard (note that the tracking events for Certified mail differ from tracking events received for other mail types - you can learn more about the certified mail tracking events here):
Please note that both the Certified Mail and Electronic Return Receipts add-on features will each receive an additional charge that is independent of one another. Both the Certified mail and the Electronic Return Receipt add-ons are only available for First Class mail sent domestically within the US. To see the incremental cost of sending Certified mail through Lob, please refer to our pricing page.