Prepaid Connection
Once activated, a prepaid connection has fixed value and fixed air time which has to be used up with in the period for which it has been issued. If the air time is not used up within the validity period, it can be carried forward, provided the connection is renewed within the period of validity.
Advantages of a prepaid connection
The first and biggest advantage that I found is that you do not have to bother for bills. Just buy the card, dial the number and your mobile is ready for use.
The second advantage is that whether you use more of SMS or make more calls, it is all covered by the value of the card.
Thirdly, you do not pay extra for Caller Line ID. It is in built in the value of the card.
Fourthly, you do not have to make any additional deposit etc for using STD ISD facility or utilising roaming facility. To make STD and ISD calls the balance value has to be beyond a certain limit.
Fifthly, you are able to know the balance value of the card by just dialing the customer care.
Disadvantages of prepaid connection
I find that the biggest disadvantage in prepaid card is that you can not know the pattern of usage since you do not get a bill. How much was used for SMS and how many calls you made and to whom all the calls were made.
The second disadvantage I find is that anyone can misuse your mobile card without your coming to know where the call was made.
Post Paid Connection
A post paid connection requires making a deposit and then choosing from a host of schemes offered for various users based on their requirement. Tariffs vary depending on the scheme you are opting for.
Advantages of a post paid connection
Firstly, a post paid connection permits you to talk unlimited without bothering to renew your connection with a card.
Secondly, you get to know exactly how much you have called and to whom all and how many SMS you have sent.
Thirdly you have the option of choosing from a variety of schemes depending on your requirement.
Disadvantages of a post paid connection
The biggest disadvantage is that the usage pattern comes into the open once the bill is received. Secret calls made tumble out of the closet.
Secondly, a lot of hidden costs are levied when the bill is received and you invariably find that you have been over billed.
Thirdly, you tend to over use the mobile, as the calls do not get cut because the value of the card has run out. This happens till you get the first bill. There after it becomes an emergency device. Once bitten twice shy.
Fourthly, you can not check your usage on a day to day basis. You have to wait till your bill is received.
I am sure there may be many other advantages and disadvantages which other readers can add.