Filing your Maine sales tax return is simple with the state’s online system. You can file and pay directly through the Maine Tax Portal (MTP), as long as your business is registered to collect and remit sales tax.
This guide will walk you through the step-by-step process of filing online so you can submit returns on time, avoid penalties, and stay compliant with Maine’s sales tax rules.
What You Need Before Filing
Before filing your sales tax return, you must prepare specific records to ensure your report is accurate. Here are the standard documents required to file a sales tax return in Maine:
- Maine Taxpayer Account Number (Sales Tax Permit) – You’re required to provide your Maine sales and use tax account number to file your sales tax return. This unique number is assigned to a business upon successful registration with the Maine Revenue Services. This number can be found on your Maine Sales Tax Permit document.
- Maine Tax Portal Account Log-in Details – The primary way to file your Maine sales tax return online is by logging into your Maine Tax Portal account. To access the site, ensure you have your log-in credentials ready (e.g., your username and password).
- Total Sales – Gather your total revenue during the filing period. It includes all sales, whether they’re taxable or not. Even if you currently have no sales records, you’re still required to file a return.
- Taxable Sales – Compile the total taxable sales your business made within the filing period.
- Taxable Purchases – A key component of compliance in Maine’s tax system is reporting use tax. Businesses are required to account for and remit tax on any taxable purchases made for business use that were not subject to Maine sales tax at the time of purchase. This applies to both in-state and out-of-state transactions.
- Bank Account and Routing Number – These details are essential for electronically paying any taxes due via an ACH Debit transaction.
- Filing Frequency Schedule – Maine assigns a specific filing frequency based on your average monthly sales tax liability, which determines your due dates. To find your designated schedule, check your Maine Sales Tax Permit.
Step-by-Step: How to File Maine Sales Tax Online
Step 1. Go to the Maine Tax Portal website. Step 2. Enter your Account Credentials: Log in using your username and password. Check your shared email/phone number and enter the OTP when applicable. Step 3. Collect your Ecommerce Sales Tax Data (e.g., Taxes Report from Shopify). Step 4. On the dashboard, click File Current Return to begin the filing process.
Step 5. Select the applicable options for your return, then click Next.
Step 6. Continue selecting the appropriate options as prompted, and click Next to proceed.
Step 7. Enter the Gross Sales amount, then click Next.
Step 8. Enter the Sales subject to 5.5% or 8% tax rates, then click Next.
Step 9. Input any additional sales that apply, then click Next.
Step 10. Enter the total amount for Rentals, then click Next.
Step 11. Review all balances and figures for accuracy, then click Next.
Step 12. Enter any additional fees or charges, then click Next.
Step 13. Click OK to proceed to the payment section.
Step 14. If applicable, add any related attachments or supporting documents, then click Next.
Step 15. When asked if you wish to proceed with payment processing, select Yes, then click Next.
Step 16. Process the payment by selecting the bank account to be used, scheduling the payment date, and entering the amount to be paid, then click Next.
Step 17. Review the payment details and balances, then click Next.
Step 18. Finalize the submission by checking the Declaration box, entering your name and surname, and clicking Submit to complete the filing process.
Step 19. Save the confirmation in your preferred location for recordkeeping purposes. Keeping online records using Google Drive is a common option.
Helpful tip: If the filing process is interrupted by internet issues, website downtime, or other disruptions. You can always click on “Save and Submit Later” to avoid losing your progress.
Due Dates
The Maine Revenue Services determines a business’s filing frequency and due dates based on its average sales and use tax liability, as established by state law under Rule 304. The following table summarizes the filing frequencies and their corresponding average monthly tax liability thresholds.
| FREQUENCY | REQUIREMENT | REPORTING PERIOD | DUE DATE |
| Monthly | Average tax liability of $600 or more per month. | Monthly | 15th day of the month following the end of each reporting period. |
| Quarterly | Average tax liability is at least $100 but less than $600 per month. |
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| Semiannual | Average tax liability of less than $100 per month but more than $50 per year. |
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| Annual | Average annual tax liability of $50 or less. | January – December | January 15 |
Due Date Filing Extensions
Retailers may apply to the State Tax Assessor to extend the due date for filing sales and use tax returns by 30 days for good cause. An authorized extension remains in effect until revoked in writing by the assessor. The extension does not extend the time for paying the tax.Timely Filing Discount
Some states offer a timely filing or “vendor discount” to compensate businesses for the administrative costs associated with collecting, filing, and remitting sales tax on time. However, Maine does not currently offer a timely filing discount. This policy shows that the state views collecting and remitting sales tax as a basic, unpaid responsibility of doing business, not a service that deserves compensation.Filing Amended Returns
Amended returns can be filed electronically through the Maine Tax Portal. You can access your account on the portal and file an amended return, just as you would with an original return, by designating it as an amendment.Refunds
In the event of an overpayment of sales or use tax, a business may apply for a refund. The specific form to use is the Application for Refund — Sales and Use Tax (Form DR-26S). A completed refund application must include:- Supporting documentation, such as a cover letter detailing the reason for the request, and proof that you paid the tax, and
- Certification that you have not requested and will not request a refund from the retailer who originally received the tax.
Filing Zero Returns in Maine
Generally, any business that is registered to collect sales tax in Maine is required to file a return for each assigned reporting period, even if there were no taxable sales and no tax is due. However, there are a few important considerations:- A business registered solely for use tax is not required to file a return for any month in which no tax is due.
- A business that has registered as a seasonal filer is not required to file returns during the months they are officially closed for business.
Other Filing Methods in Maine
If you’re having difficulties filing your Maine sales tax return online, you can try other options.- File with TaxHero – Let expert accountants in TaxHero prepare your sales tax returns for you. We’ll take everything off your hands so that you can spend your time more efficiently managing your business.
- File by mail – You can file and pay using the official Form ST-7 by mail. You can download the form and its instructions from the Maine Revenue Services website.
- Use a third-party service – Many businesses choose to use a sales tax automation or accounting service to manage their filings. These services can prepare and submit your sales tax returns on your behalf, which can save you time and ensure compliance.