Key takeaways
- An S corporation files Form BI-471 with Vermont, or the shorter Form BI-476 if every owner is a Vermont resident and all income is Vermont-source.
- A Vermont minimum entity tax of $250 is paid with the return, and tax is due on the original date even when the filing is extended.
- Nonresident shareholders trigger Form WH-435 estimated payments, and more than 50 nonresident owners makes a composite return mandatory.
- Collect the federal Form 1120-S, the owner roster with residency, and the Vermont-source income detail before you start the state return.
Which Vermont return an S corporation files
Vermont places S corporations, partnerships and LLCs under its Business Income Tax, and the standard return is Form BI-471. Payments go in with Form BI-470, the payment voucher, unless a paper form you are mailing already carries the payment.
Form BI-476 is the shorter alternative. The Department of Taxes describes it as the return for entities owned only by Vermont residents, with only Vermont-source income and loss. If a client has a single Vermont-resident shareholder and one Vermont location, BI-476 is the one to look at first. If a single owner lives in New Hampshire, you are back on BI-471.
The return does not stand alone. BI-471 carries schedules that depend on who owns the company: Form BI-472 for non-composite nonresident owners, Form BI-473 if the entity files a composite return, Form BI-477 to calculate the Vermont income adjustment for pass-through nonresidents, and Form K-1VT, the owner information statement each shareholder receives alongside the federal Schedule K-1.
Due dates and how the extension works
For calendar-year entities, the Department's 2026 calendar lists March 16 for Form BI-471, Form BI-476 or the extension application, Form BA-403, and October 15 as the extended due date for BI-471 and BI-476. March 16 and not March 15 because the fifteenth fell on a Sunday and Vermont moves weekend and holiday dates to the next business day. The federal Form 1120-S date for 2025 returns moved the same way, to March 16, 2026.
For tax year 2026 returns filed in 2027, the fifteenth of March is a Monday, so no weekend shift applies. Vermont had not published its 2027 calendar when this page was reviewed, so confirm the dates on the Department's business income tax page before putting them in an engagement letter.
The extension has two parts. Vermont says a federal extension of time to file automatically extends the Vermont filing date until 30 days after the federal extension date, and the client does not need a separate state form in that case. The federal request is Form 7004. Tax is still due on the original date, so the extension moves the paperwork and not the money.
Worked example: a client with Vermont-source income files Form 7004 and sends nothing to Vermont. The $250 minimum tax was still due on the original date. If you did not pay it with a BI-470 voucher by then, you have a late payment to cure even though the return is on extension. Put the voucher on the same task as the federal extension.
The $250 minimum tax and the federal penalties behind it
Generally a $250 minimum tax is due on the Vermont return, and the Department states that BI-476 filers pay the $250 minimum entity tax with the return. Treat it as a fixed cost of doing business in Vermont, and tell the client in the engagement letter so it is not a surprise on the invoice.
The federal side is where late penalties bite. The 2025 Form 1120-S instructions set the late filing penalty at $255 per month or part of a month, per shareholder, for up to 12 months. A three-shareholder company that files two months late owes $255 for each of three shareholders for each of two months, before any penalty on tax due. For 2025 returns, the instructions also list $340 for each late or incorrect Schedule K-1.
Those dollar amounts are the 2025 instructions, which applied to returns due in 2026. Check the 2026 instructions when they are released before quoting a number for tax year 2026 returns.
Nonresident shareholders: WH-435 and composite returns
If any shareholder lives outside Vermont and the S corporation has Vermont-source income, the entity has to pay estimated tax for that owner. Vermont uses Form WH-435 for these payments, due in installments through the year. The 2026 calendar shows January 15, April 15, June 15 and September 15 installments, with another due January 15, 2027.
The Department says plainly that the entity cannot delegate the WH-435 requirement to the nonresident. A shareholder who says they will handle it personally does not move the obligation off the company.
The entity may elect to file a composite return and pay tax at the entity level for nonresident owners. It becomes mandatory when there are more than 50 nonresident owners, a rule that began with tax year 2013. Included owners generally do not file their own Vermont return, provided they have no other Vermont income or activity, and composite filers use WH-435 for the estimates, which are credited to the composite return.
Decision rule: with one or two nonresident owners who already file in Vermont for other reasons, a composite return saves little. If a nonresident owner has no other Vermont activity and would otherwise file only for this K-1, a composite return removes a return from their stack and is worth offering.
Is there an elective pass-through entity tax?
Many states let an S corporation pay tax at the entity level so owners deduct it on the federal return despite the SALT cap. The Department's business entity income tax page does not list an elective PTE tax form or election in Vermont, and none appears in its list of pass-through forms. A Vermont bill to create one was introduced in 2023, but this review did not confirm enactment.
Do not promise a client a Vermont entity-level workaround. Before a client asks, check the Department's pass-through pages and the current session laws, and record the date you checked in the file.
Documents to collect from the client
Ask for the federal Form 1120-S as filed or in final draft with all Schedules K-1, and the Form 2553 acceptance letter if this is a first-year election. The federal instructions say not to file Form 1120-S unless Form 2553 has been filed or is attached, so a missing acceptance letter is worth catching in November, not March.
Ask for a shareholder roster with each owner's home state, ownership percentage and any change during 2026. Residency drives BI-476 versus BI-471, WH-435 and composite eligibility. A message that works: "Please send each shareholder's legal name, state of residence on December 31, 2026, and the dates of any ownership change this year." Residency is the fact most often missing.
Ask for a Vermont-source breakdown: where payroll is paid, where property sits, and receipts from Vermont customers, since Form BI-477 and the apportionment depend on it. Also ask for proof of each WH-435 payment made in 2026 and the Vermont business account number from Form BR-400.
A usable closing request for a client who is behind: "We cannot file the Vermont return until we have the owner residency list and the WH-435 payment confirmations. Please send both by the end of January so we can file before the original date." Send it with a link to the upload request.
Failure modes to catch
The common misses are a nonresident owner with no WH-435 payments made all year, an extension filed federally with the $250 left unpaid, and a K-1VT that does not match the federal K-1 because an ownership change was not reported.
A second miss is treating BI-476 as the default. If one shareholder moved out of Vermont mid-year, the entity is no longer owned only by residents, and the short form no longer fits. Ask about moves in the same email that asks about ownership changes.