Every client advisory services (CAS) engagement begins with an onboarding period across most certified public accounting (CPA) firms that unfolds like this:
This typical sequence is understood as an operational task (i.e., the work of making the engagement ready to run). Oftentimes, it’s treated as administrative and delegated to staff who connect systems and transfer files. Even the profession’s vocabulary—“implementation,” “transition,” “setup”—make this stage seem like preparation for the “real” work. But this early stage is actually more important than that—it’s the interval that determines the engagement’s structure.
When firms build their onboarding processes around the administrative logistics required to get the engagement up and running (e.g., establishing logins, collecting prior-period files, and confirming the chart of accounts), it organizes the onboarding infrastructure around access and readiness, not around defining what functions the firm will own or what access that ownership requires.
As a result, the firm behaves like an outside provider receiving access from the client, rather than as an embedded owner of certain finance functions. Ultimately, the client organizes the materials, grants logins, and sets the terms of access; the firm then receives what the client offers.
It’s important for firms to remember that onboarding establishes “control,” meaning the firm has clearly defined ownership of responsibilities and the access needed to carry them out. When defined at the onset, that ownership becomes a structural condition of the engagement. If left undefined, control doesn’t disappear—it just defaults to the client, and the firm operates on within whatever access the client extends.
There are two ways the onboarding period can establish a CAS engagement:
What separates the resulting engagements is what the onset specified before the operation began: One engagement carries a position established as a condition of its structure; the other carries a position it inherited rather than one it set.
When access is established during onboarding, it becomes part of the engagement’s structure. But when the firm asks for additional access after the work has started, that request feels like a renegotiation. By then, the client has already formed an opinion about the firm’s role.
The firm’s position is easiest to establish at the beginning of the engagement. At that point, ownership and access are inexpensive to establish. But later on, that same ownership and access can be expensive to acquire, as each addition asks the client to reopen a settled arrangement.
Ultimately, what the onboarding period should establish is the position the firm will hold, the functions it’ll own, and the access that ownership carries. What the engagement can later produce is bounded by what onboarding established.
Remember, onboarding isn’t just an administrative setup. Onboarding is the moment when the firm either defines its role or accepts the limits defined by its clients.
