There exists two possible ways to process the cash flows (cash-ins and cash-outs) of treasury deals done with a business partner: using the classic customers / vendors payment program (F110) or working with payment requests (F111). Contrarily to the traditional payment program for customers and vendors, the payment program based on payment requests does not necessarily rely on customers or vendors open items to generate payments. It is able to generate payments based on G/L account postings.
It usually makes most sense to base Treasury payments on payment requests and to clearly separate those payments from the customers and vendors payments. This is because Treasury payments are so specific with regard to their nature, the type of partners involved, the amounts exchanged, the operators processing them, …
Obviously the retained approach will impact the posting rules set-up and the payment related information that is required to be maintained at transaction and Business Partners levels to process payments properly.
It must be noted that house bank and house bank account identifiers must be provided if you want to perform a payment or if your posting rules definitions rely on bank account information (i.e. your account symbols use masks to derive G/L bank clearing accounts from actual G/L bank accounts). This latest situation is most likely to happen if you opt for the posting approach based on payment requests.
If for whatever reason you choose not to maintain the house bank account information, you should note that the reporting in Cash Management will be affected in the following way: the corresponding cash flows will be reported as cash forecast (instead of cash position) associated to a specific planning level (specified in customizing as the planning level to use for such treasury transactions when the bank information is unknown) and to the planning group of the customer that is linked to the Business Partner with whom the deal has been done.
No matter the approach retained, a dedicated payment method is usually required. The format to be associated to the payment method is to be confirmed with the house banks. It could very well be S.W.I.F.T. MT101 which is supported in standard SAP since release 4.5A.
Depending on the approach you choose, you have to fill in the single payment method field (valid for approach based on F110) or the multi payment methods field (valid for approach based on F111) in the treasury transaction and in the Business Partner master data.
In customizing, the posting rules are associated to so-called update types. This specification of the posting rules can be specialized for each of the two possible approaches. For this purpose a payment flag is found in the customizing screen used to allocated posting rules to update types. When this flag is set it means that the specified posting rule applies to the classic payment program approach.