The service provider functions are described in the following sections, in alphabetical order. The table below shows the SPI functions, the sections in which they are defined, their modes, and the API functions they implement.
| Section | WOSA/XFS SPI | Mode | WOSA/XFS API | Mode |
| 5.1 | WFPCancelAsyncRequest | Immediate | WFSCancelAsyncRequest | Immediate |
| 5.1 | WFPCancelAsyncRequest | Immediate | WFSCancelBlockingCall | Immediate |
| (none) | - | WFSCleanUp | Synchronous | |
| 5.2 | WFPClose | Asynchronous | WFSClose | Synchronous |
| 5.2 | WFPClose | Asynchronous | WFSAsyncClose | Asynchronous |
| (none) | - | WFSCreateAppHandle | Immediate | |
| 5.3 | WFPDeregister | Asynchronous | WFSDeregister | Synchronous |
| 5.3 | WFPDeregister | Asynchronous | WFSAsyncDeregister | Asynchronous |
| (none) | - | WFSDestroyAppHandle | Immediate | |
| 5.4 | WFPExecute | Asynchronous | WFSExecute | Synchronous |
| 5.4 | WFPExecute | Asynchronous | WFSAsyncExecute | Asynchronous |
| (none) | - | WFSFreeResult | Immediate | |
| 5.5 | WFPGetInfo | Asynchronous | WFSGetInfo | Synchronous |
| 5.5 | WFPGetInfo | Asynchronous | WFSAsyncGetInfo | Asynchronous |
| (none) | - | WFSIsBlocking | Immediate | |
| 5.6 | WFPLock | Asynchronous | WFSLock | Synchronous |
| 5.6 | WFPLock | Asynchronous | WFSAsyncLock | Asynchronous |
| 5.7 | WFPOpen | Asynchronous | WFSOpen | Synchronous |
| 5.7 | WFPOpen | Asynchronous | WFSAsyncOpen | Asynchronous |
| 5.8 | WFPRegister | Asynchronous | WFSRegister | Synchronous |
| 5.8 | WFPRegister | Asynchronous | WFSAsyncRegister | Asynchronous |
| (none) | - | WFSSetBlockingHook | Immediate | |
| 5.9 | WFPSetTraceLevel | Immediate | (none) | - |
| (none) | - | WFSStartUp | Immediate | |
| (none) | - | WFSUnhookBlockingHook | Immediate | |
| 5.10 | WFPUnloadService | |||
| 5.11 | WFPUnlock | Asynchronous | WFSUnlock | Synchronous. |
| 5.11 | WFPUnlock | Asynchronous | WFSAsyncUnlock | Asynchronous |
Note that in this section device drivers and devices are mentioned frequently, instead of service providers and services. This is due primarily to the fact that access to financial peripheral devices is the first category of financial services being addressed by the BSVC. However, note that in the future other financial services will be part of the WOSA Extensions to Financial Services, and will also use these interfaces, with additions as necessary. See Appendix A for more on this subject.