Delivery Receipt (DLR) FAQs

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Chase Greiser

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Table of Contents

What is a Delivery Receipt (DLR)?

What is an intermediate DLR?

What is a final or handset DLR?

How do I receive a DLR?

When will I receive a DLR?

I received an expired DLR. Does this mean my message wasn’t delivered?

What types of DLRs can I expect to see?

 

What is a Delivery Receipt (DLR)?

A Delivery Receipt (DLR) is an acknowledgement from a destination carrier network that a message was successfully accepted or rejected (and the reason the message was rejected). Bandwidth supports DLRs on SMS if a customer has their requested delivery status flag set appropriately. 

There are two types of DLRs: intermediate and final (handset).

 

What is an intermediate DLR?

An intermediate DLR (SMPP 3.4 ACCEPTD) means the end carrier has received the message and it's usually considered successful. Generally speaking, in the US and Canada market for local long codes, ACCEPTD will be the most precise indicator of a successful message. You'll mainly see ACCEPTD with P2P (person to person) traffic, specifically with long codes (10 digit local numbers).

It's important to note that some destination carriers, even after sending back an ACCEPTD, may not be able to deliver the message due to downstream spam filters or other reasons. This is on a per carrier basis. If Bandwidth does receive a clear rejection for a message, you'll always see failed messages indicated as REJECTD rather than UNDELIVERABLE.

Even though intermediate DLRs don't represent actual final delivery to a handset, knowing that your message was received at a point along the delivery path to your customer’s handset can help with troubleshooting if you receive complaints of customers not receiving messages. Also, keep in mind, all P2P routes in the U.S. and Canada only provide intermediate DLRs.

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What is a final or handset DLR?

A final or handset DLR is a confirmation that your message was delivered to the recipient’s handset and will be sent back to us as DELIVRD (SMPP 3.4). You'll mainly see DELIVRD with A2P traffic on toll free numbers and short codes (very few carriers will send a DELIVRD), but if a carrier were to send a DELIVRD, we'll send that back to you. One exception to final DLRs is Canadian traffic. On long code and toll free, Canadian carriers will only return an intermediate DLR - there are no final DLRs on Canadian traffic.

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How do I receive a DLR?

DLRs are always requested for V2 Messaging API users, but V1 and SMPP customers must have their requested delivery status flag set appropriately. More information on how to set up callbacks for HTTP can be found here: V2 APIs and V1 APIs

 

When will I receive a DLR?

Delivery receipts aren't guaranteed even when they're requested from destination operators, but when we receive them, delivery receipts are typically processed in 2 hours or less. If a DLR isn't received within 2 hours, you'll receive a DLR timeout error.  

 

I received an expired DLR. Does this mean my message wasn’t delivered?

Not necessarily! Expired means we didn't receive a DLR from the destination carrier or handset within the timeout window (the period we are ‘listening’ for DLRs). This isn't an indicator of whether or not a message was delivered.

 

What types of DLRs can I expect to see?

Messaging Reach

Type of DLR

US Short Codes

In most cases, a final / handset DLR will be sent

Zone 1 SMS - US & Canada

(US Long Codes or Text-Enabled Landlines)

Only intermediate DLRs are available. However, these DLRs still  indicate that your message has been passed to the carrier network for delivery.

Zone 1-5 SMS

(International short code or long code text-enabled numbers) 

On a case-by-case, country-by-country basis, there may or may not be DLRs available. 

 Toll Free SMS

(US Text-Enabled Toll-Free Numbers)

In most cases, a final/handset DLR will be sent. 

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