Is there a chance to post only in SAP FM but without integration to SAP FI? We want to record only incoming and outgoing payment transactions. Very simple.
I saw that the Cash desk has got a very similar functionality. In our case it wouldn't be cash payments but payments initiated from other governmental departments which are centrally not only paid but also checked against the budget.
We could just use the cash desk as well if there is a BAPI or Webservice which we can use to record the incoming and outgoing payments.
All earmarked funds post in FM without creating a financial document. The best one to use as independent consumption is Funds Block (FMW1). It all depends on your business needs, which I might say, are not quite clear from your description. I don't understand a connection of incoming/outgoing payments to budget. If those payments occur in another system and you want just to update SAP with this information, why would you do it via FM document and not via FI one? Also, payments as such are the last link in the chain of the documents flow and your budget should have been impacted well beforehand.