How Custom SMS Works?

Custom SMS is a feature in Fast2SMS in which you can send unique variable SMS to your users. In this feature just the variable value for each user changes and the overall message remains the same.

We will explain you with an example. Suppose you want to send test marks to your students in which each student scored different marks. If you use the custom SMS feature you do not need to type the message again and again. Whole message will remain the same just the variable value will get changed.


Dear Sonia
This is to inform you that you have scored 80 marks in your Physics test.

Dear John
This is to inform you that you have scored 65 marks in your Physics test.


In the above examples the variable value is name and marks. Only that has been changed, rest of the message is the same. Let us see the process of using Custom SMS feature.


How to use Custom SMS?

1. Select the route 

After selecting the custom SMS option from the left side of the panel, you need to select the route.

  • Promotional – In this route promotional SMS are sent to non DND numbers within the time frame of 9 AM to 9 PM only. If you are sending SMS after 9 PM, then automatically the SMS is scheduled for the next day morning 9 AM.
  • Quick Transactional – Custom SMS feature will not work in Quick Transactional route. Click here to read more about it.
  • Transactional – In this route you have to submit documents for verification and after verification gets completed you can send SMS to non DND and DND numbers. The SMS should be of non promotional nature. In this route, approval of each SMS template is not required. Once the transactional route is approved in your Fast2SMS account then you can send any number of SMS at any time. You don’t need our approval for sending transactional SMS. Once your documents are verified, transactional route will be approved in your Fast2SMS account. If you want to get transactional SMS approval, email us at [email protected]

Note : Custom SMS feature will work only in Promotional and Transactional route.

Custom SMS


2. Select the Sender ID

You can use default sender ID of Fast2SMS that is FSTSMS or create your own Sender ID. Click on Add New button on the right side to create your own sender ID. If you want to renew your Sender ID click on Renew option next to Add New button. Click here to know more in detail about Sender ID.

Custom SMS Sender ID

Once you click on the ADD NEW button, the following screen will show up. Click on the I AGREE TERMS & CONDITIONS button to proceed further with creating sender ID.

Custom SMS, Sender ID add


3. Next step is to upload the CSV File 

Upload your CSV File. Based on your data in CSV file, variable value will get changed. Click on Select to upload your CSV File.

CSV File can be any excel file with .csv as extension.

Note : Maximum size of CSV File can be 20 MB, not more than that.

Custom SMS CSV File

Click on Select to upload your CSV File. For your convenience, we have provided a sample CSV File. When you click on Sample File, a format of sample file gets downloaded. It looks like the image below.

Click here to download sample CSV File

How custom SMS works?

Here we have uploaded a file named marks.csv. When it gets uploaded it appears on the screen as shown below.

Custom SMS CSV file

Note : It may seem that only first 4 details are displayed but do not worry, whole file details are saved and just for the sake of visibility only the first 4 details are made visible.


4. Select the column name which has mobile numbers

Next step is to select the column name which has mobile numbers. After that, write your message in the message box and select the variable name from the above table and press send. In the example below, after writing Dear select the name variable and after writing scored select the marks variable. Then press send. When the SMS reaches to the recipients automatically their name and marks will appear in the SMS.

Custom SMS Draft

Note :    In the above message

               {#11#} denotes the first column that is the name of the student

{#22#} denotes the second column that is the marks of the student.

When you press send, confirmation dialog box will appear stating the details of the SMS. Click on Confirm to send the SMS. It will give a preview of how your message will appear in the mobile of the recipient. Also the cost per SMS, total characters, total messages, number count will be displayed.

Confirm box Custom SMS


There is a character limit for each SMS. It is different for Unicode and for English SMS.

Note – Your SMS can only include 1530 characters in total, not more than that.

Below is a list of how many characters will be counted as 1 SMS, 2 SMS, 3 SMS and so on. It describes about the character limit of SMS in English language.

Character limit of SMS

SMS Length( No of characters)SMS Count

Below is a character limit for Unicode SMS

SMS Length (No of characters)SMS Count

Note – Amount will be calculated based on the SMS count. Suppose there are 165 characters in your SMS. Then cost of 2 SMS will be deducted from your Fast2SMS wallet.

When you click on Confirm, following message will appear on your screen.

Message sent successfully Custom SMS

The SMS will appear on Sonia’s mobile as shown below

How custom SMS works?

Important Note: It is not compulsory to use variable feature in custom SMS. You can send the SMS directly also.

You can upload your CSV File containing list of mobile numbers to whom you want to send the message, then select the column name which has mobile numbers. And after that type your message and press send. The SMS will get delivered to all those mobile numbers which were there in the CSV file.

Note : If you are sending Custom SMS from promotional route after 9 PM, then a warning message will be displayed. As per TRAI rules, promotional SMS is not allowed from 9 PM to 9 AM. Your SMS will be automatically scheduled for the next day at 9 AM. The warning message will be displayed as shown in the image below.

How Custom SMS works?


5. Check delivery report after some time

To see delivery report of the SMS which you have sent, click on the Delivery Reports option on the left side. All your sent SMS will appear here. Click on the message to open it and view its status. To know more about Delivery Reports, click here. When you click on the message, another window will get open describing the details of the SMS.

Custom SMS Delivery report

The following window appears when we click on the message. Here all the message details are displayed.

how custom SMS works?

When you scroll down further, you will get all the details like status whether it is delivered, pending, DND, blocked or sent. Also the delivery time will be displayed.

how custom SMS works?

You can send Flash SMS by clicking on the icon next to schedule button. Flash SMS appears automatically on the receiver’s mobile screen without any user interaction. Click here to know in detail about Flash SMS.

When you click on the icon highlighted with red color, flash will get enabled. Now you can send Flash SMS. At the top of the screen message will be displayed that Flash SMS is enabled. To disable Flash SMS click on that icon again.

Custom SMS flash enabled


You can also write Unicode SMS in Custom SMS feature. By default English tab is selected, if you wish to send message in language other than English, select the Unicode tab. Once you have written the message in roman, press space. Automatically it will convert it in the language you wish to send the SMS. See the image below for clarification. In this example we have to select the Unicode tab and after selecting type the message text in roman. As soon as we press space bar key after typing first word, automatically it gets converted into the language we have selected.

Custom SMS Unicode


You can also schedule the SMS to be sent at a later date and time. To schedule the SMS, click on SCHEDULE, then select the Date. You can select multiple dates as well for sending the SMS at multiple times on the future dates. If you want to schedule the SMS for one time then select ONE TIME else select MULTIPLE.

In the example below we have scheduled the SMS for 8th August at 3 PM.

Custom SMS Schedule

When we select the Schedule button, a confirmation box will appear containing all the details. Click on Confirm.

how custom SMS works?


Once we click on confirm, the following message will get displayed.

Message scheduled Custom SMS


If you want to cancel the scheduled SMS you can do it by going to the delivery report section and then select the schedule tab and then click on the Cancel SMS option. Money charged for that SMS will be refunded in your Fast2SMS wallet. It is described in the image below.

Schedule SMS cancel

How bulk SMS works?

Select Yes Cancel button. Once you select it, a dialog box will appear stating that schedule bulk SMS has been canceled successfully.

Schedule SMS is cancelled


If you are scheduling custom SMS from promotional route after 9 PM, then an alert message will be displayed as shown in the below image. As per TRAI rules, you cannot send promotional SMS from 9 PM to 9 AM. And if you are scheduling the SMS, it will be automatically delivered at 9 AM(next morning).

How custom SMS works?

You can cancel the Schedule SMS if you wish to do so by visiting the Delivery Report section and select the schedule tab. After that click on the cancel SMS option to cancel the scheduled SMS.

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