Send a one-off message from a workflow, or build a sequence
A workflow may send one acknowledgement. The moment there is a second message and a wait, you are building a sequence in the wrong place. Here is the line.
Workflows are for records and state, not for talking to customers. Campaigns and sequences do the talking. There is one exception worth keeping: a single, immediate acknowledgement — "we got your form, somebody will call you" — sent once, with nothing after it. That belongs in a workflow because it is a consequence of an event, not a conversation.
The test is simple. One message, no wait, nothing after it: workflow. A message, a wait, and another message: sequence. The reason to hold the line is that customer-facing logic should live in one place, where the person reading it can see the whole cadence.

Before you start
- A channel to send on — the WhatsApp channel needs an approved template for anyone outside the 24-hour window.
- An honest answer to whether this is one message or the start of a cadence.
Steps
Decide it is genuinely one message
An acknowledgement of a form. A confirmation that a booking was made. A note that a document is ready. If the next thing you want to write is "wait a day, then", close the workflow and open Sequences.
Add the send step and choose the channel
WhatsApp outside the 24-hour window needs an approved template — and a form-filler is outside it unless they messaged you. Email tolerates length a WhatsApp would not. Pick the channel before you write.
Respect the WhatsApp window and the broadcast timings
A free-form WhatsApp to somebody who has not messaged you fails silently. And automated sends are held to the broadcast timings on the channel, so a 2am acknowledgement waits for the morning — which is a setting, not an accident.
Write it as a person would
"Thanks — we have your details and Priya will call you within the hour" beats a formal acknowledgement nobody reads.
Make sure a reply goes somewhere
People reply to acknowledgements. The channel it went out on is where the reply lands, so that channel needs a bot or a person on it. Otherwise you have manufactured silence.
If it grows, move it
The day you want to add "and if they do not reply, call them", the whole thing is a sequence: form submitted, acknowledge, wait, call, WhatsApp, task. Build it there and delete the send step from the workflow, so the customer-facing cadence has one home.
Check it worked
Trigger the workflow against your own number from outside the 24-hour window. The message should arrive once, and nothing should follow it. If you are waiting for a second message, you have built half a sequence.
The parts people get wrong
- A workflow sends once. A campaign reaches an audience across channels over time. A sequence does that for one person and can act on the record between steps.
- The send step is metered like any other action. The sequence that replaces a chain of them is usually cheaper as well as clearer.
The ones people actually ask
Can a workflow send a WhatsApp and then an email?
It can, and it should not. Two messages with a wait between them is a cadence, and cadences belong in a sequence where the person reading it sees the whole thing. Keep the workflow to one acknowledgement.
My workflow message failed for real customers but worked in testing.
The WhatsApp 24-hour window. It worked in testing because you had just been messaging yourself. Anyone outside the window needs an approved template.
An automated message went out at 2am.
Broadcast timings on the channel were not set. Automated WhatsApp is held outside the hours configured there, so a 2am send is a setting rather than an accident.