Guam runs a "mirror" tax code, meaning federal-style income tax brackets apply, but you file and pay locally to Guam's own Department of Revenue and Taxation instead of the IRS. On top of that sits a monthly Gross Receipts Tax that taxes revenue, not profit, a genuinely different rhythm from what most mainland businesses are used to. Here's what it takes to start a business in Guam in 2026.
1. Which business structure fits you?
Before you register anything, it helps to know what you're actually choosing between.
- LLC. Personal liability protection, flexible management, and pass-through taxation by default (though LLCs can elect corporate-style taxation instead). Articles of Organization cost $250.
- Corporation. Separate legal entity, more formal governance requirements, suited to businesses planning to raise capital or bring on multiple shareholders.
2. Register your business
File your formation documents (Articles of Organization for an LLC, Articles of Incorporation for a corporation) with Guam's Department of Revenue and Taxation. A distinctive requirement: Guam mandates that limited liability entities publish a formation notice in two newspapers and submit a certificate of publication within a 120-day window, non-compliance can suspend your authority to do business. Every business, including sole proprietors, needs a general business license from the DRT's General Licensing and Registration Branch, with the fee (typically $100 to 1,000) scaled to your annual gross income; renew it every year by 30 June.
3. Understand the Gross Receipts Tax
Guam's headline business tax is the Gross Receipts Tax (GRT): a flat 5% on gross income, not net profit, filed and paid monthly, and the return can only be filed online. This is worth building into your pricing from day one, since it applies regardless of your margins.
4. Check licenses and permits
Beyond the general business license, certain professions (CPAs, doctors, attorneys) need their own specialized licenses. Foreign corporations need both a business license and a Certificate of Authority from the DRT before transacting business in Guam.
5. Understand Guam's income tax
Because Guam mirrors the US Internal Revenue Code, corporate and individual income tax brackets closely track federal rates, but the tax itself is paid to Guam's Department of Revenue and Taxation rather than the IRS.
6. Stay compliant
Every LLC and corporation files a Guam Sworn Annual Report between 1 July and 1 September each year, starting the year after formation, for a $100 fee; corporations additionally report authorized shares, class, and par value. Missing the deadline by more than 60 days triggers a $50 late fee.
Guam business costs at a glance
| Item | Cost |
|---|---|
| LLC Articles of Organization | $250 |
| General business license (annual) | $100 to $1,000 |
| Gross Receipts Tax (monthly, on gross income) | 5% |
| Sworn Annual Report | $100/year |
| Late Sworn Annual Report fee | $50 |
Frequently asked questions
What is Guam's Gross Receipts Tax?
A flat 5% tax on gross income, not net profit, filed and paid monthly, applying regardless of your margins.
Does Guam use a mirror tax code?
Yes. Guam mirrors the US Internal Revenue Code, so federal-style income tax brackets apply, but the tax is paid to Guam's own Department of Revenue and Taxation instead of the IRS.
How much does it cost to form an LLC in Guam?
$250 for Articles of Organization, plus a $100 to 1,000 annual general business license fee scaled to gross income.
Does Guam require a newspaper publication notice?
Yes, a distinctive requirement: limited liability entities must publish a formation notice in two newspapers and submit a certificate of publication within a 120-day window.
When is Guam's Sworn Annual Report due?
Between 1 July and 1 September each year, starting the year after formation, for a $100 fee.
Fees and rates above come from Guam's Department of Revenue and Taxation as of 2026, and they do change over time, so double check before you file. None of this is legal or tax advice. Talk to a Guam-qualified accountant or lawyer about your specific situation.