Overview
If an automation might send the first one-to-one SMS to a phone number, that message needs your A2P 10DLC company variable in it.
You cannot always know which records that applies to, so the safe approach is to put the variable in the first SMS step of every automation. It costs nothing on records that already have a messaging history, and it protects the ones that do not.
Steps
Step 1: Open the automation
Step 2: Find the first SMS step
The first message in the sequence is the one that matters.
Step 3: Insert the A2P company variable
Use the REsimpli variable, not typed text.
Step 4: Do not add your own opt-out wording
REsimpli adds the required opt-out language automatically. Typing "Reply STOP to unsubscribe" yourself duplicates it.
Step 5: Review the remaining SMS steps
Step 6: Save and test
Test with an internal record before running it on real leads.
Important Notes
The first SMS step is the one to get right. The requirement is about the first one-to-one message to a phone number.
Add the variable even when recipients probably have message history. It is a safety net for the records where the requirement has not yet been met, and it does no harm on the others.
Do not duplicate the opt-out wording. REsimpli adds it, and since 16 September 2026 it appears only on the first message of a conversation rather than on every follow-up.
It must be a real variable. Typed text that looks like the variable will send literally.
Frequently asked questions
Do I need to add "Reply STOP to unsubscribe" myself?
No. REsimpli adds the opt-out wording automatically — adding it yourself duplicates it.
Why put the variable in the first SMS if the seller has probably been texted already?
Because you cannot be sure. It protects the sequence for any record where this automation happens to be the first one-to-one message to that number.
Do I need the variable in every SMS step?
No. The requirement concerns the first message.
Troubleshooting
The message is not sending
Confirm the A2P company variable is present in the first SMS step.
Confirm it is a valid REsimpli variable rather than plain typed text.
Check the account's A2P registration status.
On legacy plans that still use credits, check messaging credits are available.
The opt-out line appears twice
You have typed it in as well as REsimpli adding it. Remove your version.
Related
A2P 10DLC Requirements for Bulk SMS vs One-to-One SMS
A2P 10DLC Requirements When a Contact Has Multiple Phone Numbers
How to Register for A2P 10DLC in REsimpli