USA Update: September 2026 State Sales Tax Deadlines Shift to 21 September, What International Sellers Must File Today

by Ariful | Sep 21, 2026 | US Updates

US Sales Tax Deadline: 21 September 2026

If you collect US sales tax, Monday 21 September 2026 is a critical filing and payment deadline in many jurisdictions. The usual 20th-of-the-month deadline fell on Sunday, so a large group of states moved the deadline to the next business day.

This applies to international ecommerce sellers, Amazon FBA operators, Shopify merchants, digital businesses, and US importers of record. It may cover monthly returns, prepayments, quarterly returns, or related payments depending on your filing frequency.

Do not assume every state uses 21 September. Several states have different dates.

File today if your state uses the 20th-of-the-month deadline

The following states and jurisdictions generally move their standard 20th-of-the-month sales tax deadline to Monday 21 September 2026 because 20 September fell on a Sunday:

• Alabama
• Arizona
• Arkansas
• Colorado, including most home-rule city returns
• District of Columbia
• Georgia
• Hawaii General Excise Tax
• Idaho
• Illinois
• Indiana, for early monthly filers
• Kentucky
• Louisiana, where parish deadlines generally align
• Maryland
• Michigan
• Minnesota
• Mississippi
• Nebraska
• Nevada
• New Jersey, for monthly prepayments; returns are generally filed quarterly
• New York, for monthly and quarterly returns
• North Carolina, where monthly prepayment filers must also remit a prepayment towards the next month’s liability
• Oklahoma
• Pennsylvania
• Rhode Island
• South Carolina
• South Dakota
• Tennessee
• Texas
• Virginia
• West Virginia
• Wisconsin, for early monthly filers

Your filing obligation depends on the frequency assigned to your account. A monthly seller may be filing an August return. A quarterly seller may be filing a return covering the previous quarter. Some states may require a prepayment rather than the full return.

Check the relevant state revenue department before submitting. For example, New York’s 2026 filing calendar explains the state’s monthly and quarterly sales tax filing dates, while Colorado’s sales tax guidance sets out its filing rules and weekend adjustments.

Do not treat 21 September as a nationwide deadline

Several states follow different dates in September. Your compliance calendar should include the following deadlines:

• Maine: 15 September
• Florida: 18 September
• Ohio: 23 September
• Kansas, New Mexico, Vermont and Washington: 25 September
• California, Connecticut, Iowa, Massachusetts, Missouri, North Dakota, Utah and Wyoming: 30 September
• Wisconsin: 30 September for standard monthly filers
• Alaska: generally 30 September for remote seller returns in participating local jurisdictions

California also has a separate 24 September prepayment deadline for certain accounts. Its monthly August sales and use tax return is generally due on 30 September. The California Tax and Fee Filing Due Dates page confirms these dates.

North Dakota’s monthly August sales, use and gross receipts tax return and payment are due on 30 September, according to the state’s official 2026 deadline schedule.

If you missed a deadline earlier this month, submit the return and payment as soon as possible. Late filing can lead to penalties, interest, or compliance notices.

Marketplace collection does not remove your filing obligation

All 45 states with a statewide general sales tax plus the District of Columbia have marketplace facilitator laws. Amazon, Etsy and similar platforms may collect and remit sales tax on transactions processed through their marketplaces.

However, marketplace collection does not automatically eliminate your own filing obligations.

You may still need to:

• Maintain an active sales tax registration.
• File a zero return where no tax is payable.
• Report marketplace sales separately from direct sales.
• Make required prepayments.
• File quarterly or annual returns.
• Report sales made through your own website.
• Account for wholesale, B2B and other non-facilitated transactions.

Your Shopify store is not automatically covered simply because Amazon collects tax on your Amazon orders. Direct-to-consumer sales may create separate collection and reporting obligations.

Alaska, Delaware, Montana, New Hampshire and Oregon do not have a statewide sales tax. Alaska is different because local jurisdictions may impose their own remote seller and marketplace collection requirements.

Complete this checklist before the end of today

Use the following process to reduce the risk of a missed return.

1. List every state and local jurisdiction where you are registered.
   This prevents you from relying on a general national calendar.

2. Confirm your filing frequency.
   Check whether the account is monthly, quarterly, annual, or subject to prepayments.

3. Separate marketplace and direct-channel sales.
   Reconcile Amazon, Etsy and other platform reports with Shopify, WooCommerce, wholesale and B2B invoices.

4. Review exempt and resale transactions.
   Keep valid exemption certificates and resale documentation. This supports the figures on your return.

5. Check import and fulfilment records.
   If you are the importer of record, review customs entries, warehouse movements, use tax exposure and inventory destinations.

6. Submit the return, even if the liability is zero.
   A zero return may still be required. Filing it protects your account from an apparent non-filing notice.

7. Schedule or make the payment.
   Filing without paying the balance can still result in interest and collection action.

8. Save evidence of submission.
   Keep confirmation numbers, payment references, filed returns and reconciliation workpapers.

We can support this process through ongoing bookkeeping, sales tax calculations, filing preparation and compliance delivery. You provide the business data. We keep the compliance work moving throughout the year.

Worked example: a UK-owned Amazon FBA seller with a US LLC

Imagine a UK company owner operates a US single-member LLC. The LLC sells household products through Amazon FBA and Shopify.

Amazon collected and remitted sales tax on many marketplace transactions. The seller therefore assumes there is nothing to file.

That assumption may be incorrect.

The seller should first review the states where the LLC is registered or has a filing account. Suppose the business has filing obligations in Texas, Illinois, New York and California.

The September action could look like this:

• Texas: file and pay the relevant August return by 21 September.
• Illinois: file and pay the relevant monthly return by 21 September.
• New York: file and pay the relevant monthly or quarterly return by 21 September.
• California: make the 24 September prepayment if applicable, and file and pay the monthly August return by 30 September.

The seller then finishes the process by:

• Filing any zero returns required in states where only marketplace sales were made.
• Keeping all confirmation numbers and reconciliation workpapers.

That final step often matters most during a later audit.

USA Update: IRS Confirms Year-End Guidance on US-Inventory Income Sourcing, What International Sellers Must Know

by Ariful | Sep 20, 2026 | US Updates

TITLE: IRS Guidance on US Inventory Sold Abroad: What International Sellers Need to Know

Why the IRS timing matters for international sellers

If your business produces inventory in the United States but sells it through a foreign branch or overseas operation, the timing of this IRS update matters.

On Friday 18 September 2026, an IRS official reportedly said that the IRS hopes to issue guidance by the end of 2026 on sourcing income from inventory produced in the United States and sold outside the country. The guidance is expected to explain how the 2025 One Big Beautiful Bill Act changes interact with existing foreign tax credit rules.

This is an important development for international sellers, US LLC owners, Amazon FBA businesses, and companies using US inventory or fulfilment networks.

The guidance is not final yet. Until it is published, you must continue to apply the existing sourcing framework and keep clear records that support your position.

The key issue is not simply where your customer is located.

The US tax analysis can depend on:

• Where the inventory was produced.
• Where the sale was managed and completed.
• Whether the business maintains a foreign branch or fixed place of business.
• Whether a US office, warehouse, or other facility contributes to the sale.
• Whether the inventory was produced or purchased.
• How the income is allocated for foreign tax credit limitation purposes.

The IRS guidance project appears in the IRS 2025–2026 Priority Guidance Plan. The plan refers to guidance on income from inventory produced in the United States and sold outside the United States through a foreign branch.

The September announcement confirms the expected timing. It does not replace the current rules or create a filing extension. You should therefore prepare your 2026 records using the rules available today, while building a process that can be updated when the final guidance arrives.

What changed under Section 904(b)(6)?

Before the 2025 legislation, income from selling inventory produced in the United States was generally treated as US-source income for the relevant foreign tax credit limitation analysis, even where the sale took place through a foreign branch.

The 2025 law added Section 904(b)(6). The new provision allows a taxpayer to treat up to 50% of income from the sale of US-produced inventory as foreign-source income for foreign tax credit limitation purposes.

The rule applies where:

1. The taxpayer is a US person.
2. The inventory was produced in the United States.
3. The inventory was sold outside the United States.
4. The taxpayer maintains an office or other fixed place of business in a foreign country.
5. The income from the sale is attributable to that foreign location.

The change applies to taxable years beginning after 31 December 2025.

This is a targeted rule. It applies for the Section 904 foreign tax credit limitation. It does not automatically change the source of the income for every other US tax purpose.

The statutory baseline is available in Section 904 of the Internal Revenue Code. The IRS and Treasury guidance should clarify how the new rule operates alongside existing inventory sourcing regulations.

Continue using the existing sourcing framework

Until the new guidance is issued, your business must still consider the established rules under IRC Section 865 and Treasury Regulation Section 1.865-3.

These rules are particularly relevant where a nonresident maintains an office or other fixed place of business in the United States.

Produced inventory may use a 50/50 or books-and-records method

Under Treasury Regulation Section 1.865-3, income from produced inventory attributable to a US office may generally be allocated using:

• The 50/50 method; or
• An eligible books-and-records method.

Under the 50/50 method, 50% of the gross income, gain, or loss is allocated to the US office or fixed place of business. The remaining 50% is allocated to production activities and sourced under the applicable production rules.

The books-and-records method requires more detailed support. Your records must show, in good faith and without being influenced by tax considerations, how income relates to sales activities and production activities. You must also maintain the supporting explanation and records when the return is filed.

Purchased inventory is treated differently

If the inventory is purchased rather than produced by the nonresident seller, all income from sales attributable to the US office is generally treated as properly allocable to that US office.

That means you cannot automatically apply a 50/50 split to purchased inventory.

Foreign offices can affect the result

The regulations also contain an exception for certain inventory sold for use, disposition, or consumption outside the United States where a foreign office materially participates in the sale.

This is why you should document the actual functions performed in each location. Do not rely only on the location of your customer, warehouse, or marketplace account.

How this affects Amazon FBA and international sellers

Many businesses use Amazon FBA, third-party logistics providers, or US fulfilment centres. However, FBA activity alone is not a blanket safe harbour or automatic US office determination.

The analysis is fact-specific.

You should consider:

• Whether your business owns or controls inventory in the United States.
• Whether you are the importer of record.
• Who arranges customs clearance and transportation.
• Whether Amazon or another provider performs only logistics functions.
• Whether your business has employees, agents, or contractors carrying out sales activities in the United States.
• Where pricing, contracting, customer management, and sales decisions are made.
• Whether you maintain a foreign branch with genuine operational activity.

For UK sellers, this issue should sit alongside your wider ecommerce accounting and tax records. Your US activity may also need to be reviewed separately from UK VAT, customs, corporation tax, and year-end reporting.

A business can have US sales without meeting the conditions for the new Section 904(b)(6) treatment. Similarly, a US LLC owner may have reporting obligations that are separate from the foreign tax credit analysis.

For example, a foreign-owned US disregarded LLC may need to consider Form 5472 reporting and the related Form 1120 filing process. Form 5472 penalties can be significant, so do not assume that inventory sourcing is your only US compliance responsibility.

Worked example: a foreign branch selling US-produced inventory

Assume a US corporation:

• Produces goods in a US factory.
• Sells those goods to customers in Germany and France.
• Uses a properly established German branch to manage European sales.
• Earns $300,000 of gross income from the relevant inventory sales.
• Pays $45,000 of foreign income tax on the related foreign activity.

Under the new Section 904(b)(6) rule, the corporation may potentially treat up to $150,000, or 50% of the $300,000 income, as foreign-source income