Guides
Can ChatGPT or Claude Fill Out Tax Forms?
AI can help create files and populate forms. Learn why a tax PDF or spreadsheet can still fail, what to ask for, and how to move from a draft to a reviewed filing.
Acorn 9 team
Insights
Startup tax, explained.
Tax, accounting, and fundraising — from an AI-native tax & accounting firm built for startups.
Accounting
How to Check an AI-Filled Tax Workpaper
A practical review checklist for AI-filled Excel and PDF tax workpapers: trace sources, reconcile totals, preserve formulas, resolve gaps, and confirm the filing handoff.
Acorn 9 team
Tax
FBAR & Foreign Accounts: Who Must File FinCEN Form 114
It is not a tax form, it is filed separately from your return, and the threshold is just $10,000 across all your foreign accounts combined. The FBAR catches more people than almost any other cross-border rule.
Acorn 9 team
Tax
Form 5471, Explained: When U.S. Owners of Foreign Companies Must File
If you are a U.S. person with a stake in a company abroad, the information return you may owe is dense, technical, and carries a $10,000 starting penalty. Here is how to tell whether it applies to you.
Acorn 9 team
Tax
Form 5472: Why Foreign-Owned U.S. Companies Face a $25,000 Trap
If a non-U.S. person owns your U.S. LLC or corporation, you almost certainly have a filing obligation most software never mentions — and the penalty for missing it starts at $25,000 per year.
Acorn 9 team
Tax
LLC vs S-Corp vs C-Corp: Choosing the Right Entity as a Founder
The entity you pick shapes how you are taxed, how you raise money, and how much paperwork you carry for years. There is no universally best choice — only the right one for your plan.
Acorn 9 team
Accounting
Monthly Close & Clean Books: What Investors Actually Look For
"Clean books" is more than tidy spreadsheets. It is the difference between closing a round in weeks and stalling in diligence while you reconstruct a year of history under pressure.
Acorn 9 team
Tax
Estimated Taxes: How to Avoid the Quarterly Underpayment Penalty
The U.S. tax system is pay-as-you-go. If you wait until April, you can owe a penalty even when you pay your full bill on time. Who owes estimates, the four due dates, and the safe harbor that protects you.
Acorn 9 team
Tax
Cross-Border Structuring: Building a US-Asia Company the Right Way
A U.S. entity, an overseas parent, payroll in two countries, and a web of filings — cross-border companies are where structure mistakes get expensive. The order of operations matters more than founders expect.
Acorn 9 team
Tax
Why Founders Incorporate in Delaware (and When You Shouldn't)
"Just do a Delaware C-corp" is startup gospel — but it is right for some founders and wrong for others. Here is what Delaware actually buys you, and when to skip it.
Acorn 9 team
Tax
Running a US Startup from China: A Founder's Tax Guide (2026)
Chinese founders with a Delaware C-corp face a heavier US tax stack: Form 5472, §174 foreign R&D on a China team, and cross-border capital. A field guide.
Acorn 9 team
Tax
Section 174: R&D Capitalization After OBBBA (2026)
OBBBA restored immediate expensing of domestic R&D in 2026 — but foreign R&D is still capitalized over 15 years. The offshore trap, with a calculator.
Acorn 9 team
Tax
State Franchise Tax & Annual Report Deadlines for Startups (2026)
Franchise tax and annual reports for the 13 states startups actually use: deadlines, fees, and minimums for Delaware, California, Texas and more.
Acorn 9 team
Tax
The 83(b) Election: A Founder's 30-Day Guide (2026)
Filing an 83(b) within 30 days of a restricted-stock grant can save founders a fortune, and missing it is unfixable. How and when to file, plus a checker.
Acorn 9 team
Tax
Multi-State Tax Nexus for Startups: The Remote-Team Trap (2026)
One remote hire can create income-tax and payroll duties in a new state. Wayfair sales-tax nexus is a separate trap. Where SaaS is taxed, plus a self-check.
Acorn 9 team
Tax
QSBS After the 2025 Overhaul: The Founder's Guide to Section 1202 (2026)
OBBBA rewrote QSBS for stock issued after July 4, 2025: tiered holding periods, a $15M cap, a $75M asset ceiling. What qualifies and how much is tax-free.
Acorn 9 team
Tax
R&D Tax Credit for Startups: 2026 Rules, Section 174, and the Payroll Offset
OBBBA restored domestic R&D expensing. Most startups get a 6% credit they can offset against payroll taxes, up to $500K. How it works, with a calculator.
Acorn 9 team
Tax
Delaware Franchise Tax: The Complete C-Corp Founder's Guide (2026)
What Delaware franchise tax is, how the two methods work, and why your default bill may say $85,000 when you could legally pay $400. With a calculator.
Acorn 9 team
Tax
The First-Year Startup Tax Checklist (2026)
Every federal and state tax task a new startup owes in year one: EIN, the S-election clock, your first return, payroll, and why domestic firms skip BOI.
Acorn 9 team
Fundraising
Burn Rate and Runway: A Founder's Primer
What burn rate and runway actually mean, how to calculate them, and the runway investors expect at each stage — with an interactive calculator.
Acorn 9 team