I am building site for a client in .NET. The site has a monthly subscription service, wherein customer pay for the services with debit/credit card details. Money will be deducted from the account regularly. Customers can cancel the subscription service at any time and the collection should be stopped.
Is there any service that I can use to accomplish this? Any information on how to go about developing this will be much appreciated.
Thanks in advance.
PayPal is ideal for this. See:
https://www.paypal.com/en_US/ebook/PP_NVPAPI_DeveloperGuide/Appx_SDKDotNET.html
Most payment processors I have worked with support recurring payments. This means that you don't have to store the credit card information. Typically you just store a reference to the credit card and just send the process the amount and the reference number to complete the transaction after the initial payment.
This is one of the companies I have worked with and their details of how recurring payments work. PayPal also does recurring payments.
Can i suggest you review all the other posts on SO regarding monthly payments? This search does bring back a number of questions that may be of help to you (it also brings back a few non related ones, just ignore those :)
If you want to outsource the entire billing system (which is certainly advisable, as they can be an extremely complex distraction), I would recommend working with a company like http://spreedly.com/ or http://chargify.com/, who do exactly this and provide an extremely simple API (especially compared to PayPal) to integrate with your .NET app.
Bear in mind that with these solutions you still need to bring your own payment processor and merchant bank account.
If the merchant account is US based you should consider Authorize.Net's Automated Recurring Billing API. It handles the subscriptions for you and has a very easy to use API. They offer working sample code to get you started.