Sign In Scheduling sends out thousands of SMS messages every day using Twilio alongside some other providers. Delivery issues are unusual, but can sometimes occur.
There are lots of factors at play in the SMS delivery process. This guide explains how to understand those that might impact the successful delivery of your messages.
How to recognize SMS delivery or failure
To check whether an SMS message has been successfully delivered, you can take a look at the conversation history for the booking in question.
Your conversation history can be found by clicking on the relevant booking within your calendar. This will open a sidebar to the right. The conversation history will be visible within the activity window.
You'll find a record of all messages here - both SMS and Email. SMS messages are marked by a speech bubble icon:
Whilst emails are marked by an envelope icon:
When an SMS message has been successfully sent and delivered to your customer, you'll see a double tick underneath the message.
If the message has been sent but not yet delivered, you'll see a single tick underneath the message. This means that Sign In Scheduling has sent the message to the customer, but it hasn't yet come through to the customer's phone, and they won't have received it yet.
This can happen if the customer's phone is off or out of signal range. The message will usually be delivered eventually, once the customer's phone is back on and receiving a signal.
When an SMS message hasn't been sent or delivered, you'll see an 'X' symbol underneath the message, notifying you that the message has been rejected.
Why would a message be rejected?
1. The most common cause of SMS rejection is an incorrect phone number. The customer's number might have changed, they might have made a mistake when entering it, or accidentally included an extra character.
We recommend checking for any obvious errors in the phone number, and confirming that it's definitely a mobile number. Sign In Scheduling can't send SMS messages to landline numbers. Check that the customer hasn't recently changed their number, too.
2. SMS messages can fail to deliver if the customer's phone is out of range or powered off for a long time.
If the message status changes from 'Sent' to 'Rejected', we recommend reaching out to the customer another way to check whether they've had their phone powered off or out of range recently.
3. SMS messages can sometimes fail to deliver if there's a discrepancy between the country you selected when you signed up, and the numbers you're trying to send messages to.
If you're sending SMS messages to local numbers, check that the country set for your account is correct. Head to 'Setup' > 'Business Details' to review your selected country.
4. Although very rare, it's possible that our SMS provider could be down, resulting in SMS rejection.
You can check our service status page by clicking here. Any issues will be posted there.
Network limitations & filtering
Sometimes, mobile networks block or filter certain content as a security measure, which can occasionally result in problems with SMS delivery. We explain how this might happen below, and what you can do about it.
You can customize your sender ID under 'Setup' > 'Extra SMS Settings'. Customizing the sender ID is sometimes known as SMS spoofing. Essentially, this changes the way the sender of the SMS appears to your customers. Changing the sender ID to your business name would mean that the customer sees your business name as the sender, rather than an unknown phone number.
A customized sender ID could be blocked or filtered by a mobile network. It's not always easy to predict what might trigger this, but certain keywords are more likely to be flagged than others as an anti-spam measure. Adjusting or changing your customized sender ID is one step you can take to secure the successful delivery of your messages.
SMS short name
You can customize your SMS short name under 'Setup' > 'Extra SMS Settings'. Your short name will usually be the name of your business, so that your customers know who the message is from. Whatever you input as your short name will appear at the beginning of each message, e.g. 'From Sign In Scheduling:'.
SMS messages can fail to deliver due to being blocked or filtered because of the SMS short name. In much the same way and for the same reasons that they'd flag your sender ID, mobile networks might flag your SMS short name. We recommend adjusting or changing your customized SMS short name to see if that helps.
Message content & booking link
If the SMS message contains content that a mobile network thinks could be suspicious, they might block or filter the message for that reason, resulting in SMS rejection. Each SMS message from Sign In Scheduling also contains a link that your customers can use to view more information about their booking. Occasionally, mobile networks might enact a block because of the presence of that link.
You may wish to review and amend the content of your SMS messages to avoid blocking and filtering. In extreme circumstances, we might remove the booking link from an SMS message to improve delivery rates with certain mobile carriers.
Need more help?
If you're facing issues with your SMS delivery, contact us as soon as possible so we can discuss the next steps.
Unfortunately, if a network decides to block or filter your messages, there's very little we can do from our side as we have no control over this. Nevertheless, we'll work with you to try and find a solution where possible.