SMS Message Credits#
What is a Message Credit?#
SMS message credits are the “currency” used when dealing with SMS messages. A single message can use up to 9 message credits.
Caution
You should take extra care when sending messages with replacement tokens in as the message size will be updated according to the value of the token and could increase the number of credits a message uses.
How is a Credit Calculated?#
The number of credits your message uses is calculated based on the number of characters in the message.
A single SMS can contain up to 160 characters and uses 1 credit.
You can send a message larger than a single SMS and up to a total of 9 messages and 1377 characters (9 credits would be used). When sending messages that exceed the character count of a single SMS the message broken up into chunks of 153 characters. This is required in order to link the messages up again when they are received by the phone (called concatenation).
The table below shows the credits that would be used in each scenario up to the maximum of 9 credits:
Number of SMS |
Maximum Characters |
Number of Credits |
|---|---|---|
1 |
160 |
1 |
2 |
306 |
2 |
3 |
459 |
3 |
4 |
612 |
4 |
5 |
765 |
5 |
6 |
918 |
6 |
7 |
1071 |
7 |
8 |
1224 |
8 |
9 |
1377 |
9 |
Tip
See Valid SMS Message Characters for more information about the characters and the special cases where a character uses up 2 spaces.
How Many Credits Will My Message Use?#
This depends entirely upon two factors; The number of characters in your message and the number of recipients the message is sent to. Some example scenarios have been laid out below.
Scenario 1#
You send a message with the following content to a single recipient. “The school term starts on the 14th October”.
This message contains 42 characters, meaning it will use 1 message credit per recipient.
You can calculate the total cost of sending this SMS by multiplying the number of credits by the number of recipients.
1 (credit) x 1 (recipient) = 1 (credit)
Scenario 2#
You send a message with the following content to a year group. “The school term starts on the 14th October”.
This message contains 42 characters, meaning it will use 1 message credit per recipient.
Lets say your year group contains 100 students and you’re sending to their priority 1 and 2 contacts, meaning if each student has 2 contacts your sending to 200 recipients.
You can calculate the total cost of sending this SMS by multiplying the number of credits by the number of recipients.
1 (credit) x 200 (recipients) = 200 (credits)
Tip
Not all students would necessarily have these contacts present therefore this represents your maximum possible credits for this message.
Scenario 3#
You send a message with the following content to a year group. “The $$CustomerName$$ school term starts on the 14th October”.
This message contains 43 characters and a replacement token ($$CustomerName$$). This means the exact size of the message is unknown at this point. The replacement token is replaced with the value you’ve configured in your School Name app setting. For the sake of this example, lets say that this value is set to “MYA Academy”, which contains 15 characters.
This gives us a message with the following content “The MYA Academy school term starts on the 14th October”. This contains 58 characters, meaning it will still use 1 message credit per recipient.
Lets say your year group contains 100 students and you’re sending to their priority 1 and 2 contacts, meaning if each student has 2 contacts your sending to 200 recipients.
You can calculate the total cost of sending this SMS by multiplying the number of credits by the number of recipients.
1 (credit) x 200 (recipients) = 200 (credits)
Tip
Not all students would necessarily have these contacts present therefore this represents your maximum possible credits for this message.
Caution
The value of your app setting could make your message use additional credits. You should review a message carefully before sending to avoid spending more than intended.
Scenario 4#
You send this message to the whole school. “Dear Parent/Guardian. Please note that $$CustomerName$$ is closed today (10/11/17) because of the severe weather. Please assume that unless you hear otherwise the school is open as usual tomorrow (11/11/17).”.
Lets use the value “MYA Academy” for the replacement token again, meaning the final message is “Dear Parent/Guardian. Please note that MYA Academy is closed today (10/11/17) because of the severe weather. Please assume that unless you hear otherwise the school is open as usual tomorrow (11/11/17).”. This is 206 characters long, meaning it would use 2 message credits per recipient.
You select to send the message to students, priority 1, 2 and 7 contacts and staff members. This might mean a calculation of:
1500 (students) + 1500 (priority 1 contacts) + 1500 (priority 2 contacts) + 1500 (priority 7 contacts) + 250 (staff members) = 6250 (total recipients)
You can calculate the total cost of sending this SMS by multiplying the number of credits by the number of recipients.
2 (credits) x 6250 (recipients) = 12,500 (credits)
Tip
It’s unlikely that all students have all contact priorities defined so calculating the recipients in this way provides a maximum number. The actual number is likely to be lower than the one used in this example.
Caution
The value of your app setting could make your message use additional credits. You should review a message carefully before sending to avoid spending more than intended.