Where the code is
Open Conversations and find the message marked unsuccessful. A failed message can show a Try again option, and it's tempting to press it straight away. Hover over the warning indicator first, or select it, to see the delivery details.
Learn More in those details opens HighLevel's troubleshooting article for that specific error. Write the code down. It's the one fact the rest of the fix depends on, and you'll want it if the problem ends up with Support.
Read the code, then decide. Try again comes last.
Three common codes and what they mean
HighLevel keeps a list of common unsuccessful SMS errors. These three cover very different causes:
- 30003: the destination handset is unreachable. The phone may be off, out of signal, or on a line that can't receive texts.
- 21610: the contact has opted out, or SMS DND is enforced on them. This one is about consent, not delivery.
- 21211: the destination number is invalid. Look at how it's written on the contact record.
30003, up close
Twilio's error reference describes 30003 as an unreachable destination handset. The causes it lists are a phone that's switched off, a weak signal, or a line that can't take SMS at all.
A single 30003 points at the recipient's side first. A pattern is different. When 30003 keeps coming back across long-code or toll-free sending, Twilio notes that carrier filtering can be involved as well.
It also isn't always permanent. A phone that was off gets switched back on. The code by itself can't tell you which of these causes you're looking at, so treat it as a lead to check, not a verdict on the number.
What to do for each code
Work through it in this order, and only resend once the cause is dealt with.
- Open the conversation and find the unsuccessful message.
- Read the warning details and follow Learn More for that code.
- For 30003, the questions are power, signal and whether the line can take SMS. If you can reach the person another way, confirm their current mobile number.
- For 21211, correct the number on the contact record before anything else.
- For 21610, don't resend. The contact has opted out or is under SMS DND.
- If the same failure keeps happening across contacts, save a few recent examples with their codes and take them to HighLevel Support.
Habits that make a failed text worse
Each of these starts from skipping the code:
- Pressing Try again on every failed message before reading why it failed.
- Deleting a contact after one 30003, when the phone may only have been switched off.
- Resending to a contact who came back with 21610.
- Leaving a 21211 number as it is and hoping the next send works.
Rather have it set up for you?
We check your sending numbers and registration and work through the failed texts code by code, starting with a 30-minute 1:1 with Rob.