How SMS Workflows Handle Manual Replies in Sparkforge

By Sparkforge Support Team ·Last reviewed May 3, 2026

If a user sends a manual SMS while a contact sits in a Wait for Customer Reply step, Sparkforge cannot attribute the reply to the right message and the contact gets stuck. Avoid manual SMS during active SMS workflows.

This is a common Sparkforge workflow gotcha: a contact gets stuck on a Wait for Customer Reply step because someone sent them a manual SMS in the middle of the automation.

The scenario

A contact is enrolled in a workflow. The workflow sends an automated SMS, then pauses on a Wait for Customer Reply step. While the contact is waiting, a user on your team sends them a manual SMS from the conversation view.

Why the workflow breaks

SMS does not have threading the way email does. There is no In-Reply-To header, no message ID, no way to know which outbound SMS a reply is answering.

When two outbound SMS messages exist (the automated one and the manual one), Sparkforge cannot reliably tie the contact's reply to the workflow message. The Wait step does not see the reply as the trigger it is waiting for, so the contact keeps sitting there.

What you will see

Contact replies to your manual message.
The Wait for Customer Reply step does not advance.
The contact is stuck mid-workflow until you intervene.

Recommendations

Do not send manual SMS to contacts who are currently in a workflow with a Wait for Customer Reply step.
If you need to reach a contact mid-workflow, remove them from the workflow first or use a different channel.
For two-way conversations during automation, design the workflow itself to handle the back-and-forth.

Frequently Asked Questions

What does the Wait for Customer Reply step actually wait for?

It waits for an inbound SMS from the contact after the workflow has sent them an outbound SMS. The system attempts to attribute the reply to the most recent outbound message in that workflow path.

Why does email threading not have this problem?

Email replies carry an In-Reply-To header that links them back to a specific outbound message. SMS has no equivalent, so there is no reliable way to attribute a reply when multiple messages have been sent.

What happens to a contact stuck at the Wait step?

They sit there indefinitely unless you manually advance them, remove them from the workflow, or the Wait step has a timeout that eventually fires and routes them down a fallback branch.

Can I add a timeout so contacts do not get stuck forever?

Yes. Configure a timeout on the Wait for Customer Reply step. After the timeout elapses, the contact moves down the no-reply branch instead of waiting forever.