Can I be my own BOC-3 process agent?
Technically yes, in your home state only - but in practice no, because the FMCSA requires an agent in every state where you operate, and you cannot be physically present in 50 states. Carriers always file through a registered process-agent provider.
The BOC-3 form has 50 lines (one per state plus D.C.). Each line names a person or company physically located in that state who can accept legal service on the carrier's behalf. You can name yourself on the line for your home state - assuming you maintain a physical address there - but you cannot legally name yourself on the lines for the other 49 states unless you actually have offices there.
Even in your home state, the FMCSA only accepts BOC-3 submissions from process-agent providers who are registered with FMCSA as process agents. That FMCSA registration as a blanket process-agent company is the upstream step ("I am a registered process agent") that the FMCSA verifies before accepting any BOC-3 that names you.
In practice, every interstate carrier files through a third-party blanket-of-coverage provider. The provider has agents on file in every state under its own FMCSA process-agent registration and submits the BOC-3 listing themselves on every line.
Self-designation is most relevant for very large carriers with formal legal departments and physical presence in multiple states. For everyone else (single-truck owner-operators through mid-size fleets), a blanket provider at $75 one-time is the standard route.