As you may already know, Exotel maintains the list of phone numbers subscribed to TRAI regulated DND (Do Not Disturb) / NCPR (National Customer Preference Registry). In general, a phone number subscribed to DND should not be dialed for marketing/commercial calls. Exotel differentiates these as transactional calls and promotional calls

Currently, Exotel does not allow outgoing calls to DND numbers. But if a DND number has called your Exotel number previously in the last 6 months we allow Transactional calls to be made to that number.

We understand that this may pose a business problem for you as you may want to contact a registered customer who has not called you on your Exotel number yet. For Eg: A customer who has registered on your website to your product/service.

As another step to help you, we're happy to introduce the Customer Whitelist API which allows you to add your DND clients' phone numbers into the Exotel's system thereby allowing you to call them if they wish to be contacted. Note that this whitelisting is also valid only for the next 6 months, post which you will have to ask your customer again if they wish to be contacted.

How does it work ?

1) You use the Customer whitelist API and add your DND customers' numbers into the Whitelist

2) An SMS is automatically sent to these numbers asking them their permission for you to contact them. 

Sample SMS: You've registered with <Your-company-Name> and permitted us to call you. If this is not the case, please give a missed call to 09XXXXXXXX. Thank you.

3) If the person does not want to receive calls from you, s/he can 'unsubscribe' by giving a missed call to a specified number (in the sms). Following this you will not be able to call him/her.
You can choose the brand name that goes in the opt-in SMS (<Your-company-Name> in the above Sample SMS). You can edit this in the "Brand Name" field in the company info page

4) Once you have 'whitelisted' a DND number, you can make outbound transactional calls to that number

IMPORTANT: If more than 3 people 'unsubscribe', then the process for whitelisting will change.
Now, instead of getting a number that is on DND to 'unsubscribe' by giving a missed call, for you to be able to call him/her, the number will have to 'subscribe' by giving a missed call. Steps 3,4 will change accordingly. The following steps will then take place.

2.a) Sample SMS: You've registered with <Your-company-name>. As you're on DND, please authorise us to call you by giving a missed call to 09XXXXXXXXX.
3.a) If the person wants to receive calls from you, they would have to give a missed call on the given number. Until that, you would be unable to contact that number

This is done to ensure that this whitelist API is used genuinely and only for transactional calls.

In case you find any constraints while using the Whitelisting API, do please have us notified via hello@exotel.in so we may address them accordingly. 

SMS senderID and costs

The above mentioned SMSes are sent from your registered sender ID (given along with every Virtual number) and the cost of the SMS (26 ps/sms) will be deducted from your account.

API Specs

API specifications are at Whitelist API description page in our Developer portal

[Update - 22 Aug, 2017] - We've updated the Whitelisting duration (effectiveness) from 2 months to 6 months and NCPR Agreement would no longer be required to use the same.