Ask HN: What is the best billing system?

At M5hosting.com we use Ubersmith. Its designed for hosting and it supports everything on your list. We are very happy with it, and the company is very responsive to support and to feature requests etc. I have never been entirely happy with a billing system, but Ubersmith is the best for us and we are very happy. Perhaps the worst software I have ever bought ot used was ModernBill (maybe now called Parallels billing). Good luck.

You could use WePay.

The API is solid, has good documentation, and supports multiple types of recurring payments. People can pay you with a credit card or bank account.

https://www.wepay.com/developer/reference

What do you do for international payments?

Chargify: http://chargify.com

I want to add a couple more to the list...

http://www.accumulus.com/

http://www.zuora.com/

Braintree: http://www.braintreepaymentsolutions.com/

Braintree looks interesting - would I be able to get rid of Freshbooks + Authorize.Net + our merchant account with this service?

Also, is it US only?

Yes, it's all combined. You need a US corporation to signup I believe.

Billmax, hobviously