SERVING SAIPAN, TINIAN & ROTA REMOTELY · SINCE 2005
Northern Mariana Islands Bookkeeping Services
Last Updated: October 7, 2026The CNMI has no retail sales tax — it taxes your gross revenue instead, and the brackets are cliffs, not margins. Cross a Business Gross Revenue Tax threshold and the higher rate applies to your entire gross revenue, not just the amount above the line. Add a two-layer payroll withholding system, a separate monthly bar and occupancy return, and two brand-new construction taxes, and generic accounting settings do not survive contact with CNMI filing.
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Saipan, Tinian and Rota owners and their CPAs come to us because the BGRT brackets are non-marginal cliffs that a percentage-rate setting gets wrong, because CNMI payroll has two withholding layers that have to net against each other, and because construction clients picked up two new taxes in 2025 and 2026. Dedicated bookkeepers, monthly reconciliations, and tax-ready financials — plans from $75/month, extra hours at $15/hour, and wholesale $10/hour rates for CPA firms — backed by a 100% money-back guarantee on your 1st retainer, refundable on the unused balance.
On This Page
- The CNMI small-business tax landscape
- The brackets are cliffs, not margins
- CNMI payroll has two withholding layers
- Two new construction taxes, two new returns
- Licensing is Finance, not Commerce
- CNMI islands we serve
- CNMI FAQs
The CNMI Small-Business Tax Landscape
| Tax / Filing | Rate / Basis | Deadline |
|---|---|---|
| Business Gross Revenue Tax (BGRT) | Graduated on total gross revenue: $0–5,000 no tax; $5,001–50,000 1.5%; $50,001–100,000 2%; $100,001–250,000 2.5%; $250,001–500,000 3%; $500,001–750,000 4%; $750,001+ 5% — applied to the whole amount, not marginally | Monthly on Form OS-3105, by the last day of the following month |
| Wage & Salary Tax (Chapter 2) | Graduated from 0% on the first $1,000 to 9% above $50,000 annually — again applied to the whole amount at the applicable rate | Quarterly on Form OS-3705; annual Form OS-3710 and W-2CM by 28 February |
| NMTIT (Chapter 7) | The Northern Marianas Territorial Income Tax — a mirror of the federal income tax, filed on Form 1040CM, with a rebate of up to 90% of the CNMI-source liability | Federal calendar |
| Bar tax and hotel occupancy tax | 10% of alcoholic beverage charges on licensed premises; 15% of transient occupancy charges (stays under 90 consecutive days) | Monthly on Form OS-3300, by the 20th — a separate return from the BGRT |
| CNMI Construction Tax | 3% of gross revenue from non-residential construction, where construction revenue subject to the tax exceeds $350,000; residential housing and subcontractor revenue are exempt | Monthly on Form 3500CT-C1, effective 1 April 2026 |
| Saipan Construction Activity Tax | 1% of Saipan construction gross revenue above a prorated $350,000 exemption — Saipan only, not Tinian or Rota | Monthly on Form 3500CT, effective January 2025 |
| Excise tax on imports | By commodity — 1% foodstuff, 3% construction material and machinery, 5% catch-all, rising to 60% on tobacco — plus a 0.42% Environmental Beautification Tax on consumer goods on top | Within 30 days after entry |
| Business licence | Issued by the Division of Revenue and Taxation on Form BUSL-1000, priced per business activity — $100 for most businesses, more for regulated sectors | Annual fee; confirm your renewal date with DRT |
4 CMC §§ 1202, 1301 and 1708; CNMI Department of Finance, Division of Revenue and Taxation Forms OS-3105 (Rev. 12/2024), OS-3300, OS-3705, BUSL-1000, 3500CT and 3500CT-C1; CNMI Public Law 23-31 and Saipan Local Law 23-24; checked 5 October 2026. Rates, forms and effective dates change — confirm with the Division of Revenue and Taxation or your CPA. Note that third-party summaries describing BGRT as a quarterly filing are wrong; the official return is monthly.
The Brackets Are Cliffs, Not Margins
This is the error we see most often in CNMI books, and it is expensive in both directions.
Federal income tax brackets are marginal: you pay 10% on the first slice, 12% on the next, and so on. The CNMI’s Business Gross Revenue Tax does not work that way. The statute expresses each bracket as a percent of the amount over $0 — so once your gross revenue crosses a threshold, that rate applies to the entire figure.
The practical effect is a cliff. A business at $749,000 of gross revenue sits in the 4% band. At $751,000 it sits in the 5% band, and the 5% applies to all $751,000 — not to the $1,000 above the line. The same mechanic applies to the Chapter 2 Wage & Salary Tax, whose official instruction is to multiply the full amount by the applicable rate.
The $5,000 floor behaves the same way: it is an exemption that disappears, not a deduction you subtract from the base. A configuration that treats it as a $5,000 reduction is wrong for every business above the floor.
Any generic percentage-rate setting in an accounting file will get this wrong, because it will apply the rate marginally or subtract the floor. The BGRT return is also cumulative year-to-date, carrying prior-month gross revenue forward, so a single mis-set month propagates for the rest of the year.
CNMI Payroll Has Two Withholding Layers
CNMI employers withhold twice from the same wages, under two different regimes, and the two have to net against each other.
Chapter 2 withholding uses the CNMI’s own Wage & Salary Tax tables. Chapter 7 withholding — NMTIT, the mirror of the federal income tax — uses the federal withholding tables in IRS Publication 15-T. Because Chapter 2 tax is a non-refundable credit against Chapter 7, the amount actually withheld for Chapter 7 is the Publication 15-T figure minus the Chapter 2 amount.
Get that netting wrong and you either over-withhold, which your staff notice immediately, or under-withhold Chapter 2, which nobody notices until the quarterly OS-3705 is filed. It is the most common CNMI payroll misconfiguration we encounter, and it is a near-certainty in any system set up from mainland guidance.
There is a current example worth knowing about. The federal deductions for tips and overtime enacted in July 2025 apply asymmetrically in the CNMI: the Division of Revenue and Taxation has announced that they do not reduce Chapter 2 tax — tips and overtime remain fully taxable there — while they do reduce Chapter 7. A payroll system configured from mainland guidance will under-withhold Chapter 2 on every tipped and overtime dollar.
Two New Construction Taxes, Two New Returns
If you build anything in the CNMI, your filing obligations changed twice in eighteen months.
The Saipan Senatorial Construction Activity Tax took effect in January 2025: 1% of Saipan construction gross revenue above a prorated $350,000 annual exemption, filed on Form 3500CT. The proration is month-by-month — roughly $29,167 in January, rising each month — so the exemption is not simply $350,000 available from day one. It applies to Saipan only; Tinian and Rota clients do not file it.
The CNMI Construction Tax took effect 1 April 2026: 3% of gross revenue from non-residential construction, where annual construction revenue subject to the tax exceeds $350,000, filed on Form 3500CT-C1. Residential housing revenue and revenue earned as a subcontractor are exempt — which makes the contractor-versus-subcontractor distinction and the residential-versus-commercial split real bookkeeping categories, not just project labels.
Since April 2026 a Saipan commercial builder files both construction returns, alongside the BGRT return. The practical bookkeeping requirement is revenue tagged by island, by residential or non-residential, and by contractor or subcontractor role, from the first invoice — because reconstructing those splits at year end from project names does not work.
Licensing Is Finance, Not Commerce
A detail that costs new CNMI businesses time, and that many third-party guides get wrong: the business licence is issued by the Department of Finance, Division of Revenue and Taxation, on Form BUSL-1000. The Department of Commerce Registrar handles something different — entity registration for corporations, LLCs and partnerships. They are two separate steps with two separate agencies.
The licence fee is charged per business activity and summed if you have several: $100 for most businesses, $300 for sectors including utilities, financial intermediation and health care, $500 for commercial banking, $1,000 for offshore banking, and $20 for a temporary small-event licence.
Licensing is also where your CNMI tax identification number and your Tax Activity Code are assigned, one per activity. The Tax Activity Code is what gets reported on the monthly BGRT return — so a business whose actual activities have drifted from what it licensed will be reporting revenue under the wrong code, month after month.
The Division simplified the application in January 2026, moving compliance verification to after issuance rather than before. Onboarding checklists written against the old sequence are out of date.
CNMI Islands We Serve
We serve businesses on Saipan — Garapan, Susupe, Chalan Kanoa and San Vicente — and on Tinian and Rota, all remotely, with overnight turnaround across the time difference. The island matters for filing here: the Saipan construction tax does not apply on Tinian or Rota. See also Guam. Browse all locations.
CNMI Bookkeeping FAQs
Does the CNMI have a sales tax?
No. There is no retail sales tax in the CNMI — nothing is added at the register. The Business Gross Revenue Tax is imposed on the business, on its total gross revenue, and filed monthly. In the books that makes BGRT your own tax expense accrued on revenue, not a liability collected from customers, which is the opposite of how a mainland accounting file is configured by default.
If I cross a BGRT bracket, do I only pay the higher rate on the excess?
No, and this is the CNMI’s biggest bookkeeping trap. The brackets are not marginal. The statute expresses each as a percent of the amount over $0, so crossing a threshold applies that rate to your entire gross revenue. A business at $751,000 pays 5% on all of it. The $5,000 floor works the same way — it is an exemption that disappears once you are above it, not an amount you subtract.
How often do I file the BGRT return?
Monthly, on Form OS-3105, due by the last day of the following month — so January’s return is due at the end of February. Some third-party guides describe it as quarterly; that is wrong. The December return doubles as the annual summary, with a separate section for January through November, and bad-debt exclusions can only be claimed on the December return.
Do I file a separate return for a bar or hotel?
Yes. Bar tax at 10% of alcoholic beverage charges and hotel occupancy tax at 15% of transient occupancy charges are reported together on Form OS-3300, due the 20th of the following month — in addition to the monthly BGRT return, not instead of it. The two liabilities cannot be offset against each other, which means you need both tracked separately in the ledger from the start.
We are a Saipan contractor. Which construction tax do we file?
Since 1 April 2026, likely both. The Saipan Senatorial Construction Activity Tax (1%, Form 3500CT, from January 2025) applies to Saipan construction revenue above a prorated $350,000. The CNMI Construction Tax (3%, Form 3500CT-C1, from April 2026) applies to non-residential construction revenue above $350,000, exempting residential housing and subcontractor revenue. We tag revenue by island, by residential or commercial, and by contractor role so both returns can be produced from the same ledger. Which applies to a specific contract is a question for the Division or your CPA.
Can you work with our CNMI CPA?
Yes. We keep the monthly books and reconcile the accounts so your CPA has a clean trial balance for the BGRT, Chapter 2, construction and 1040CM filings. CPA firms get our wholesale rate of $10/hour. We are a bookkeeping and tax preparation company, not a CPA firm — we do not provide audit, attest or audit-defence services.
Do you have offices in the Northern Mariana Islands?
No, and we would rather say so plainly than imply otherwise. We are a fully virtual bookkeeping company — founded in Vienna, Virginia on May 25, 2005 and headquartered in San Juan, Puerto Rico today, US-registered with delivery centers in India, which we disclose on our About page. We have served businesses across the US territories remotely since 2005. You get a dedicated bookkeeper with plans from $75/month, monthly reconciliations, and a 100% money-back guarantee on your 1st retainer, refundable on the unused balance.
Related Resources
Cliff Brackets, Two Payroll Layers, Clean Books
Dedicated CNMI bookkeeping from $75/month — with a 100% money-back guarantee on your 1st retainer, refundable on the unused balance.