── ── Tax & compliance
The Forms Were Never the Hard Part. The Jurisdiction Question Was.
August 18, 2026 · 7 min read · By Brad Ju
Scoping a tax engagement should produce two lists, not one: the forms likely in scope, and what you still have to determine. The second is the more useful one — a form list presented alone reads as a conclusion, and the most common scoping error is a missed jurisdiction rather than a missed form.
"I sold some crypto, my wife started consulting, and we have a rental in another state." One sentence from a prospective client, and inside it are six forms, two states, and at least three questions that have to be answered before anyone can quote the job.
The instinct is to answer with a form list. That's the part software and experience both handle well, and it's not where engagements go wrong. This is the third of four CPA/EA skills we published as open source, and its central rule is that the output is always two lists.
Two lists, and the second one matters more
One list is the forms likely in scope, each with the specific fact that puts it there. The other is what you still have to determine, each with what it would change. A form list presented on its own reads as a conclusion, and it isn't one — it's a hypothesis built from whatever the client happened to mention.
There's a gate: never present the in-scope list alone. And a diagnostic that follows from it — if the to-determine list comes back empty on a real engagement, the scoping didn't happen. On a live client it never is empty.
The most common scoping error is not a missed form
It's a missed jurisdiction. Clients describe their year as a story, and forms attach to events — so the method is to decompose the story into discrete elements and then ask about location for every element separately. Not once for the client, once per element.
The trigger list is the portable part, because clients volunteer none of it:
- Residence during the year, and the date of any move.
- Physical presence for work in another state, including short stays.
- Remote work performed from a different state than the employer's.
- Property owned, rented out, or sold elsewhere.
- Business activity, customers, employees, contractors, or inventory in other states.
- Pass-through ownership where the entity operates somewhere the owner doesn't.
- An entity formed in one state and operating in another.
- Local income taxes at city, county, or district level.
Every "yes" on that list is a potential filing, a potential apportionment question, and a fee the quote didn't include. This is where scoping errors turn into unbillable work rather than into a conversation.
Ask about foreign accounts by function, not by name
Anything foreign expands scope sharply and carries reporting that sits outside the income tax return entirely — filed with a different agency, on its own schedule. Name it as a separate deliverable in the engagement letter or it gets missed.
The screening question is the part worth stealing. Clients do not classify a foreign pension, a foreign policy with cash value, a brokerage account left behind after emigrating, or signature authority over an employer's or a relative's account as "a foreign financial account." Asking "do you have anything overseas?" reliably returns no. Ask what they can sign for, not what they own.
The cheapest screen available is already in front of you: the interest-and-dividends schedule carries foreign account and foreign trust questions, on a schedule you're completing anyway. Don't let the software default them.
What the two-list output looks like
| Section | What goes in it |
|---|---|
| LIKELY IN SCOPE | Each form, with the specific client fact that puts it in scope |
| TO DETERMINE | Each open question, with what it changes — plus the thresholds, dates, or eligibility tests to verify against current guidance |
| JURISDICTIONS | Federal, each state, each foreign obligation — every one with its triggering fact |
| NOT ADDRESSED | Valuations, elections requiring analysis, positions requiring research |
Then convert it into a document request, because each form implies source documents. Working backwards is also a check: if a form is in scope and you cannot name the document that will support it, either the form doesn't belong or you've found a real question for the client.
One sentence, two filings nobody priced
New client: "I moved to Texas in June, sold my old house, and I do consulting." Decomposed, that's a part-year residency in the origin state, a principal-residence sale, and a sole proprietorship. The forms are the easy part.
Asking about location element by element produced two facts the client hadn't connected to tax at all: the consulting had two clients in a third state, and the old house had been rented for four months before the sale. The first added a state exposure question; the second converted the sale from one analysis into two, because a period of rental use sat inside the ownership period. A quote built from the client's original sentence would have been wrong by two filings.
Why this belongs before the quote
"It's a simple return" describes the forms you already know about. Simplicity is a conclusion of scoping, not an input to it — and the fee is usually fixed before anyone tests it. Run the decomposition first and the two-list output becomes the scope section of the quote, which is also the document you point at when a state filing shows up in March.
Use it or fork it
Form Finder is one of four CPA/EA practice skills we open-sourced under MIT at github.com/deciqAI/knowledge-skills — copy the folder into .claude/skills/, or paste the Markdown into any model. It maps situations to form families and to the questions that resolve them, and it carries no thresholds, limits, phase-outs, or dates by design: those expire, and the skill's job is to tell you where to stop and verify. Educational content — not tax advice.
FAQ
What should scoping a tax engagement produce?
Two lists: the forms likely in scope, each tied to the specific fact that puts it there, and the questions still to be determined, each with what it would change. The in-scope list should never be presented alone, because on its own it reads as a conclusion.
What's the most common scoping mistake?
A missed jurisdiction, not a missed form. A rental in another state, months of remote work, a mid-year move, or an owner living in a different state from the entity each add a filing that nobody priced.
How do you ask a client about foreign accounts?
By function rather than by name. Clients don't think of a foreign pension, a policy with cash value, an account left behind after emigrating, or signature authority over someone else's account as a foreign financial account — so ask what they can sign for, not what they own.
Why not rely on tax software to prompt for the right forms?
Software prompts on data entered. It cannot prompt on a state you never asked about, or on an account the client never mentioned, which is exactly where the expensive omissions live.
When should scoping happen relative to the quote?
Before it. 'Simple return' is a conclusion of scoping, not an input, and the two-list output is what the scope section of the quote should be built from.