Then, when you've proven your product, and got substantial sales, you can write your own. Maybe.
The author of the article spent weeks and thousands of euros to implement a payment system. And yet he had only a handful of customers.
Seems like most of his time was spent dealing with tax issues, which you'd have to do regardless of how money is actually transferred.
I meant that you should use a service last FastSpring or Avangate initially, which require no coding, and completely take care of VAT.
https://www.taxamo.com/braintree-announce-partnership-taxamo...
I am definitely not interested in hand-coding a solution.
I use them together with Stripe as my gateway, it generates proper invoices and applies the rate of the buyer's country unless a valid VAT number has been provided. They also provide a stripe-like js library so that the credit-card number doesn't go through my server.
With regard to VAT MOSS report, they do most of the checks, I only wrote a little ETL script using http://www.kiba-etl.org/ to create a break-down of the related amounts for each quarter and each country, which I then submit manually to the VAT MOSS French website.
So in my case, this is fully automated, and I'm pretty happy with this :-)
Feel free to email me if you have questions.
1. Generate different PayPal buttons for different countries (depending on IP). The country of the IP is included in the receipt. Currently I only have Sweden and "other".
2. For other countries, I'll manually ask the user to confirm the transaction (the intention is to make it count as a manual transaction, so I can simply use 25% VAT of my country). If the user doesn't respond I'll have to issue a refund.
Foreign users are _very_ uncommon in my case, so it works for me (my software is specific to my country anyway). I'm not even VATMOSS registered, only VAT registered.