Messages not getting delivered is frustrating at the best of times. This is particularly true for our customers—NGOs, humanitarian organizations, research universities—who often need to react to emergencies, or get messages out that people rely on.

In this article, we will discuss the various reasons why your WhatsApp messages might not get delivered—and what to do about them. We sorted the list from clearest to most obscure error.

We mention other companies here that are also active in the WhatsApp Business space, and link to them because it’s useful, but that doesn’t mean we endorse them. Note that most of these companies provide WhatsApp message delivery—while we offer WhatsApp Surveys.

#1 Not online

The person you’re trying to message isn’t online.

How to fix: Nothing much you can do—but if the phone is on and has phone signal, you might be able to get a message through on some other, low-tech channel, like SMS or voice calls.

#2 Not a WhatsApp number

The number you’re trying to contact doesn’t have a WhatsApp account—or that account is considered inactive by Meta.

How this might look like:

• engageSPARK: Not a WhatsApp number
• Meta: 1006 – Resource not found  /  1013 – User is not valid
• Twilio: 63003 – Channel could not find To address / 63024 – Invalid message recipient

Details:

If there is indeed no WhatsApp account behind this number, there may be all kinds of reasons for this: Perhaps there was a problem during data entry—maybe a typo in the number, maybe the person had multiple numbers and gave the wrong one.

But, if the number is confirmed to be a WhatsApp number, here are other reasons for this error:

How to fix:

If the contact does not have a WhatsApp account there is obviously not that much you can do. However, if this is indeed an active phone number then chances are you might be able to get a message through on some other, low-tech channel, like SMS or voice calls. Note that you can check if a phone number is valid & active using an HLR lookup.

If the WhatsApp account is there, you might want to confirm via other methods (SMS, in person, …) that they accepted the Meta Terms of Service and updated the app to the latest version.

#3 Outside the 24h session

You sent a normal message, one that isn’t a registered template, to someone you are not in an active conversation with.

How this might look like:

• engageSPARK: “Sending outside the allowed time window” — If you’re one of our customers and struggle with how the 24h session works, please reach out to support.
• Meta: 470 – Re-engagement message
• Twilio: 63016 – Failed to send freeform message because you are outside the allowed window. If you are using WhatsApp, please use a Message Template.
• Vonage: 1340 – Outside of the allowed window—This message is sent outside of the allowed response window.

Details: In short, when using WhatsApp Business, you can’t just message people. Instead, they either need to message you first, or you send them a “template message” that has been pre-approved by Meta. If they message you or reply to a template, then you have 24h to send them further messages. Whenever they reply, the 24h countdown resets. We’ve written more about 24h sessions and the difference between a session message and a template message in this support article. See also #5.

How to fix: You need to send a template message, not a session message. Alternatively, you can ask the contact to message you first—this depends on the program you’re running, of course.

#4 Your template hasn’t been approved (yet)

Your message failed because your template is either still pending approval or has been rejected by Meta.

How this might look like:

• engageSPARK: Internal error
• Meta: 2060 – Template Rejected
• Twilio: 60242 – WhatsApp template not found

Details: If you register a template, it takes a few minutes until Meta decides whether to approve or reject your template. You can’t use it before.

How to fix: Wait until Meta gives you feedback. There is no way to speed this up.

#5 Your previous marketing template has not been answered

You sent this contact a marketing template before, and they haven’t replied. Your next template message is rejected.

How this might look like:

• engageSPARK: Blocked by Meta — This error needs special care so if you’re one of our customers, please reach out to our support.
• Twilio: 63049 – Meta chose not to deliver this WhatsApp marketing message

Details: There are various types of template messages. You need to choose one when you register it. One of them is “marketing”, and for our purposes here this means that the contact isn’t waiting for this message—you are trying to reach out anyway. Because of this, Meta restricts these templates to keep the annoyance factor for WhatsApp users low.

The restriction goes like this: you messaged them—but they didn’t reply. That probably means they didn’t want to hear from you, and the probably also don’t want to hear from you again. So, Meta restricts you from spamming them, basically.

How to fix: There is nothing you can do about the short-term ban, but read on, there may be hope yet.

First, let’s re-iterate there is nothing you can do right now to lift this restriction on sending marketing templates. Nothing. Meta controls the eco system, their rules are opaque, ever-changing and enforced likely without much human intervention. There is no support to reach out to to reason with. (A warm welcome to the age of AI and algorithms.) So, wait a day or so—it’s totally unclear how long the restriction lasts—until you can message again.

Just because you ran into this ban now doesn’t mean that you’re doomed to run into it again and again though. It depends a bit on your situation. Here are ways forward:

• Use another template type, if possible. Check your message and the requirements for other template types carefully. Can you perhaps use a utility template—which does not suffer from these restrictions? A word of warning: don’t lie. If you pretend to message people under false pretenses and they report your messages … that will seriously harm the reputation of your sender—and may get you banned permanently. This solution might not be surefire as this forum entry seems to indicate.
• When sending marketing templates, always ask for a response (and make it easy to do so). This is for next time: We recommend using a simple button template, where your contacts can tap the “yes” button so the 24h window opens.
• Ask them to start the conversation. If they start the conversation, the 24h session opens and you’re good to message them. Because then it’s clear (to Meta) that they want to hear from you. So, find ways so that they message you first. This depends on the program you’re running, but perhaps a SMS reminder can be of use.

#6 Your WhatsApp sender hit its messaging limit

Every WhatsApp sender has a limit attached to it—the number of contacts you can reach out to with template messages in a 24h window.

How this might look like:

• engageSPARK: WhatsApp daily limit reached; please retry tomorrow
• Meta: 429 – Rate limit hit
• Twilio: 63018 – Rate limit exceeded for Channel

Details: The limit is being adjusted automatically—based on how much it was used previously, and how the reputation of your sender is holding up. (See #8.)

For more details, read this article by Twilio here, it’s a good one. But to cut it short, if you use more than half of your current limit while your reputation stays good, you’re in for an upgrade after 7 days.

How to fix: There is nothing you can do right now to increase the limit. There are two ways forward:

• Monitor the limit and your message quality, and expand your usage as the limit increases. Note you must use at least half of the current limit to be eligible for an upgrade.
• Spread your messages out over more WhatsApp senders. (Limits apply here, too.)

#7 The per-user limit for marketing templates

The WhatsApp user you’re trying to message has been receiving too many marketing templates and is being shielded from receiving more

How this might look like is identical to #5 above, where your previous marketing template hasn’t been answered:

• engageSPARK: Blocked by Meta — This error needs special care so if you’re one of our customers, please reach out to our support.
• Twilio: 63049 – Meta chose not to deliver this WhatsApp marketing message

However, the details are different: It’s important to understand that the limit does not apply per sender: other organizations can “saturate” the limit and prevent you from reaching out to a contact. In other words it may not be your fault at all. (Unfortunately, that doesn’t help you.)

How to fix: Like with #5 above, there is nothing you can do about the short-term ban itself. But read on, there may be hope yet.

First, about the short-term ban: there is nothing to be done to lift this restriction on sending marketing templates. Even if it wasn’t your fault and this is the first message you ever wanted to send to that contact. There is no support on Meta’s side to reach out to and reason with. (Again a special welcome to the age of algorithms.) So, you’ll have to wait a day or so—it’s totally unclear how long the restriction lasts—until you can message again. And then be faster than other businesses.

Just because you ran into this ban now doesn’t mean that you’re doomed to run into it again and again though. It depends a bit on your situation. Here are ways forward:

• Use another template type, if possible. Check your message and the requirements for other template types carefully. Can you perhaps use a utility template—which does not suffer from these restrictions? A word of warning: don’t lie. If you pretend to message people under false pretenses and they report your messages … that will seriously harm the reputation of your sender—and may get you banned permanently. This solution might not be surefire as this forum entry seems to indicate.
• When sending marketing templates, always ask for a response (and make it easy to do so). This is for next time: We recommend using a simple button template, where your contacts can tap the “yes” button so the 24h window opens.
• Ask them to start the conversation. If they start the conversation, the 24h session opens and you’re good to message them. Because then it’s clear (to Meta) that they want to hear from you. So, find ways so that they message you first. This depends on the program you’re running, but perhaps a SMS reminder can be of use.

#8 The reputation of your WhatsApp sender is ruined

Sounds a bit dramatic, but that’s what it essentially means when the quality rating for your WhatsApp sender is low.

How this might look like—yes, like #6, it’s not immediately obvious where the problem is coming from, so you need to check this:

• engageSPARK: WhatsApp daily limit reached; please retry tomorrow — if you’re a customer of ours, please reach out to our support, so we can help you understand and deal with this
• Meta: 471 – Spam rate limit hit
• Twilio: 63018 – Rate limit exceeded for Channel

Details: Twilio discusses quality ratings here. Basically, people treat your messages like spam, and so Meta is blocking you from sending further messages. This might mean contacts block your sender, or report your messages as spam, or nobody ever engages with your messages.

The reputation (“quality rating”) is updated continuously, so as the messages you send are received better, your reputation will improve.

How to fix, assuming your messages are wanted—those of our customers typically are wanted and often expected.

• Send less often. In particular, don’t send messages directly after.
• Increase engagement: When sending template messages, always ask people to respond. It doesn’t matter if you need the reply—Meta needs to see that people are okay receiving these messages.
• Make it easy to engage: We recommend to always include a button in your template messages
• Honor opt-outs: If someone sends in STOP or QUIT or any such opt-out messages, you must immediately stop messaging them.

Did this article help you get your WhatsApp messages delivered? If yes, that’s great! If not—and you’re a customer—please reach out, we’ll want to look into this, if we haven’t yet.