I am using Paypal Restful API for direct payment from my site . Currently I am testing my first implementation on sandbox.
I am not sure why merchant and buyer account is not "synchronised". After I make transaction, my merchant account receives funds but it is not reflected to buyers balance. This is import for me beacuse I am trying to test case when my client hasn't enough funds for payment.
I am not sure what respone I will recive for this case. I assume I will get respone with state "failed" for this case but I would like to clarify this if someone had same problem.
Even if i create a new buyer (personal) account with 0$, my transaction using this account completes fine. I allways get state "approved" in paypal response ( /v1/payments/payment ) even if transaction is not fully completed (etc. status "Unclaimed" - when paypal ask to change currency ). This also worries me.
And second question, do i need to implement webhooks/ipn if i am using restfull api?
I have forgot to answer on my question :D. Paypal support gave me a few useful information. At the moment I used paypal restfull api there was no option to do full negative testing, etc. to pay 0.75$ and expect specific response. This was able only for older api. I was able only to test payment status (pending, completed). For this purpose you should enable Payment review from your sandbox account settings page and use USD or GBP (i'm not sure which one) in order to reproduce this status. Also, merchant and buyer account should not be "synchronised".
And I didn't implement webhooks or ipn for my project.