Make call or SMS in Zero balance

How to make a call or want to send SMS but you have Zero balance ?

Few service providers like Airtel, Vodafone, Reliance and Idea have a service of "call with zero balance".
Using this service you can ask the service provider to allow you to call or SMS during emergency.

Airtel:
Airtel users use "call me back" service by just dialing #141 from their prepaid mobile number and you see a new window that has several options like share talktime, gift packs, ask for talk time and call me back the SMS. You have to select the option of your favor. The user can send up to 5 "call me back" SMS per month for free.

Vodafone:

Vodafone users can transfer their balance to a friend of the same circle by just dialing *131*MRP*Friend's number#, MRP is the balance you want to share with your friend. Vodafone applies charges to you and the condition for using this service is both the users should have been on Vodafone network for a minimum of 90 days.

Idea Cellular:

Idea cellular's service "Idea lifetime" allow their consumers to make a call with zero balance The user has to dial 53567 and a balance of Rs. 3 will be credited. This credit of Rs. 3 will be detected when the user recharges his number.

Reliance:

Reliance  started the Mera Network service through which users can make a call at zero balance. To activate this service, the user has to send an SMS stating ACT CC to 53739.