If you have unfiled Maryland sales and use tax returns or an unpaid balance, address both promptly: file every missing return, pay what you can, and contact the Comptroller of Maryland about the remaining balance. A late sales and use tax return is generally subject to a penalty of 10% of the tax due, plus interest. The interest rate changes, so calculate the amount using the rate for the relevant period rather than relying on an old estimate.
Maryland uses a single statewide sales tax rate rather than local jurisdictions administering their own sales taxes. But the taxability of digital products and services can be less straightforward: Maryland explicitly taxes certain digital products, and SaaS may be taxable depending on how it is sold and used. Maryland Tax Connect is the state’s system for filing and managing business tax accounts. If your past-due balance involves digital sales, cross-border transactions, or several missing periods, have the facts reviewed before filing corrections.
How to calculate Maryland back sales tax and penalties
Start by identifying every Maryland filing period that is missing or may be incorrect. Reconstruct the sales, taxable transactions, tax collected, and any tax you should have collected for each period. Separate taxable sales from exempt or nontaxable transactions and retain the records supporting that treatment. For ecommerce sellers, the review should include product type, customer location, transaction records, and whether tax was collected at checkout.
Calculate the unpaid tax for each period, then add the applicable late penalty and interest. The Comptroller’s sales and use tax return instructions state that a late return with tax due is subject to a penalty of 10% of the tax due, plus interest. Interest accrues on unpaid tax from its due date until payment, and the applicable rate can change. Use the Comptroller’s current instructions or ask the Comptroller to confirm the calculation for each period; do not apply a current rate retroactively without checking.
Maryland’s statewide rate does not mean every transaction is taxed alike. Certain digital products are taxable, and SaaS may fall under different tax treatment depending on the product and its use. The Comptroller’s Technical Bulletin No. 56 explains that SaaS can be treated as a digital product or a taxable service in specified circumstances. If your historical taxability analysis is uncertain, document the assumptions and get the classification checked before submitting returns.
Understand Maryland late-filing penalties and interest
For a late sales and use tax return with tax due, the Comptroller’s instructions specify a 10% penalty on the tax due, plus interest. A late return can also affect eligibility for a collection discount. The amount owed can therefore be more than the original tax, even when the business has stopped making Maryland sales.
Interest is charged on unpaid tax from the due date until it is paid. This one varies by seller and by state, and it is the kind of detail we check for clients as part of the service — get in touch and we will confirm where you stand. Confirm the current and historical rates with the Comptroller before finalizing a balance. Filing an extension, if one applies, does not necessarily extend the time to pay.
Do not assume that a late filing caused by a portal transition or another special circumstance automatically qualifies for relief. Any temporary relief has specific periods and conditions. Ask the Comptroller whether a particular waiver or adjustment applies to your account and filing periods.
File missing Maryland sales and use tax returns
File each required return, including a zero return if one is required for a period with no reportable activity. Use Maryland Tax Connect to access the business tax account and submit sales and use tax returns. The Comptroller’s filing system identifies the applicable period and due date; if a due date falls on a weekend or holiday, the return is due the next business day.
Before filing, reconcile the return to sales records, marketplace reports, invoices, payment processor data, and tax collected. Keep a copy of each filed return and the records used to prepare it. If you discover that a previously filed return understated tax, determine the Comptroller’s current process for correcting that period rather than silently changing figures on a later return.
If the Comptroller has already issued an estimated assessment because a return was not filed, submitting the missing return may help establish the actual liability, but it does not automatically cancel the assessment or related charges. Contact the Comptroller promptly and follow the instructions on the notice. If you are unsure which periods remain open or required, ask the Comptroller to confirm your filing obligations.
How to pay Maryland sales tax you owe
Maryland business taxpayers can use Maryland Tax Connect to file and pay sales and use tax and manage their state tax account. The Comptroller also identifies BillPay as an online payment option for existing liabilities. Check the account and payment instructions before sending funds so the payment is credited to the correct tax type and period.
If you cannot pay the full balance, file the missing returns anyway and contact Business Tax Collections to discuss a payment arrangement. The Comptroller says businesses should pay overdue balances immediately when able, and that a payment plan does not remove the obligation to file future returns on time. Keep confirmation numbers and copies of payment records.
Do not assume that making a partial payment stops interest or collection activity on the remaining balance. Ask the Comptroller how payments will be applied and what remains due, including penalties and interest. If a notice gives a specific payment method or deadline, follow the notice or contact the office using the details printed on it.
Respond to a Maryland sales tax assessment
Read the assessment notice carefully. Check the tax periods, tax type, amount, stated reason, response deadline, and contact information. Compare the assessment with filed returns, sales records, payment confirmations, and any correspondence. If the assessment appears to result from a missing return, gather the records needed to prepare and submit the actual return.
If you dispute an assessment, the Comptroller’s online appeal information says to file an appeal within 30 days of the date on the notice. The appeal process begins with a review of whether the request is timely and whether the matter can be resolved from the documents provided; a hearing may be scheduled if needed. Submit a clear explanation and supporting records, and retain proof of submission. If the 30-day period has passed, contact the Comptroller promptly because the office may ask you to explain why the assessment is incorrect.
An appeal and a payment-plan request are different steps. The Comptroller’s appeal information directs businesses seeking a payment plan to Business Tax Collections. Do not ignore a notice while deciding whether to appeal or arrange payments; contact the office using the notice details and confirm what action is required to protect your position.
When Maryland may waive penalties or interest
Penalty or interest relief depends on the facts, the type of charge, and the applicable law and Comptroller procedures. Do not assume that a first-time late filing, financial hardship, or a good-faith mistake automatically qualifies. Contact the Comptroller of Maryland, explain the circumstances, and ask what relief may be available for the specific periods and charges on your account.
Provide a concise timeline and supporting documents, such as records of a payment problem, a corrected return, or correspondence relevant to the delay. Continue to file required returns and pay what you can while a request is being considered. A request for relief does not itself establish that charges have been removed, so verify the account balance after the Comptroller responds.
Some relief may be limited to defined circumstances or periods. For example, the Comptroller has published transition-related relief for specified business filing periods; that does not establish a general waiver for other late returns. Check the current Comptroller guidance and the dates that apply to your account.
What happens if you leave Maryland sales tax unpaid
An unpaid balance can continue to accrue interest, and the Comptroller may send notices seeking payment or a required return. If a required return remains unfiled after notice, the Comptroller’s collections publication says an estimated assessment may be issued and an additional penalty may apply. An estimate may not reflect your actual sales, so respond with accurate records rather than leaving it unchallenged.
The Comptroller may pursue collection of a tax debt, including through a lien or levy where authorized. Whether a particular collection action is available or has been taken depends on the account and applicable procedures. Read every notice, respond by its stated deadline, and contact Business Tax Collections to discuss the balance or a payment arrangement.
Unpaid business tax can also create personal-liability exposure for certain people under Maryland law. The statute addresses vendors who fail to collect or pay sales and use tax and specifies circumstances in which liability extends to certain corporate officers, owners, LLC members or managers, and LLP partners or managers. The details depend on the entity’s structure and governing documents, so obtain advice based on the actual facts rather than assuming that limited liability prevents personal exposure.
Explore payment plans for overdue Maryland sales tax
The Comptroller says businesses unable to pay overdue taxes immediately should contact the Business Collections Section to discuss possible payment-plan arrangements. The Comptroller’s guidance states that a short-term plan not exceeding six months typically will not result in a lien being filed, while agreements longer than six months require review by a collections supervisor. These are general statements, not a guarantee that a plan will be approved or that a lien will not be filed in a particular case.
The Comptroller’s published contact options for Business Collections include 410-649-0633 and 1-888-614-6337, and the published email address is cdcollectionbizz@marylandtaxes.gov. Confirm current contact details on the Comptroller’s site before sending sensitive information. Be ready to provide the account information, balance, proposed payment amount, and a realistic explanation of the business’s ability to pay.
A payment arrangement does not replace required returns or resolve a disputed assessment by itself. Keep filing future returns and paying current liabilities on time, and ask how the arrangement affects collection activity and the allocation of payments. If the balance is disputed, separately follow the assessment appeal instructions and deadlines.
Who may be personally liable for unpaid sales tax
Maryland law provides that personal liability for sales and use tax, interest, and penalties extends to a buyer who fails to pay tax as required and to a vendor who fails to collect or pay tax as required. The exact position here depends on your own facts, so it is worth confirming with the state directly or talking to us about your situation. For an LLC, it identifies all members when there is no operating agreement, or the individuals who manage the business and affairs when there is one.
For an LLP, the statute identifies all general partners if there is no written partnership agreement, or the individuals who manage the business and affairs if there is one. These rules make entity documents and actual management roles important. A business owner should not assume that incorporation or an LLC automatically prevents personal liability for sales tax collected from customers but not remitted.
Whether a particular person is liable depends on the entity type, governing documents, role, and facts surrounding the tax. If you receive a notice asserting personal liability, review the cited periods and legal basis promptly and seek qualified advice. The Comptroller can explain the account and notice, but a professional familiar with the business’s structure can help assess individual exposure.
Get help resolving Maryland back sales tax
Resolving back tax usually means coordinating three tasks: reconstructing the transactions, filing accurate returns, and addressing the resulting balance or assessment. A service staffed by people can help organize sales records, review product taxability, prepare missing filings, and communicate next steps. For Maryland sellers, digital products and SaaS deserve particular attention because the tax treatment can depend on the product and its use.
Sales Tax Compliance USA is a done-for-you US sales tax service for ecommerce and cross-border sellers, not filing software. We can help review the facts, identify missing periods, prepare a resolution plan, and support the filing and payment process. We cannot promise that the Comptroller will waive charges, approve a payment plan, or accept a disputed position.
If you have received a notice, share its date, tax periods, and response deadline when asking for help, while protecting sensitive account information. The exact position depends on your circumstances; confirm it with the Comptroller of Maryland or ask us to review the facts and help determine the next steps.
Maryland transaction categories that can affect a back-tax review; confirm the treatment of each specific transaction with the Comptroller of Maryland.
| Transaction or issue | Maryland treatment to check |
|---|---|
| Ordinary taxable sale of tangible personal property | Include in the sales and use tax review; verify the applicable tax and period using the Comptroller’s current return instructions. |
| Digital product sold to a Maryland customer | Certain digital products are explicitly taxable; identify the product and transaction facts rather than treating all digital sales alike. |
| SaaS for individual use | The Comptroller’s Technical Bulletin No. 56 describes SaaS sold for individual use as a taxable digital product subject to the 6% rate. |
| SaaS for commercial use in an enterprise computer system | The bulletin describes a 3% rate where SaaS is a taxable service for commercial use in an enterprise computer system; the precise facts and applicable rule should be checked. |
| SaaS that could fit more than one taxable category | The Comptroller says the higher rate applies when different rates could apply to a digital product or taxable service; confirm classification and use. |
| Maryland local sales tax administration | Maryland is not a home-rule sales tax state; local jurisdictions do not administer their own separate sales tax in place of the statewide system. |
Frequently asked questions
What is the penalty for filing or paying Maryland sales tax late?
The Comptroller’s sales and use tax instructions state that a late return with tax due is subject to a penalty of 10% of the tax due, plus interest. The amount can depend on the period and account facts, so confirm the calculation with the Comptroller.
How much interest does Maryland charge on unpaid sales tax?
Interest accrues on unpaid tax from its due date until payment, and the applicable rate can change. The Comptroller’s business tax collections publication lists 10.5% per annum, but you should verify the rate for each tax period with the Comptroller rather than applying that figure to every period.
How do I pay back sales tax owed to Maryland?
File missing returns and pay through Maryland Tax Connect, or check the Comptroller’s BillPay option for an existing liability. If you cannot pay in full, contact Business Tax Collections to discuss a payment arrangement and confirm how payments will be applied.
Can Maryland waive sales tax penalties or interest?
Relief depends on the charge, the applicable rules, and your circumstances; a late filing or inability to pay does not automatically qualify. Ask the Comptroller about relief for the specific periods and provide supporting records. Verify any approved adjustment on your account.
What happens if I don’t pay Maryland sales tax?
Interest can continue to accrue, and the Comptroller may send collection notices or issue an estimated assessment if a required return remains unfiled after notice. Collection actions may follow, and certain people may have personal-liability exposure under Maryland law. Respond to notices promptly and contact Business Tax Collections.
Can Maryland place a lien or levy my bank account for unpaid taxes?
The Comptroller may pursue collection, including a lien or levy where authorized, but the action and timing depend on the account and applicable procedures. Contact the Comptroller using the details on your notice to understand the status and discuss resolution options.
How do I dispute a Maryland tax assessment?
Review the notice and supporting records, then use the Comptroller’s appeal process. The Comptroller’s online appeal information says to file within 30 days of the notice date; include a clear explanation and documents supporting your position. If that period has passed, contact the Comptroller promptly.
Is a business owner personally liable for unpaid Maryland sales and use tax?
Maryland law extends liability in specified circumstances to vendors and certain corporate officers, owners, LLC members or managers, and LLP partners or managers. The people covered depend on entity type, governing documents, and management roles. Review the statute and obtain advice based on the business’s actual structure and facts.
How we handle this for you
The mechanics in Maryland are manageable on their own; the cost is the time it takes every single filing period, in every state you are registered in. We are a managed service: our team registers you with the Comptroller of Maryland, prepares and files your returns, and keeps you compliant period after period. You get one point of contact and one invoice — you do not get another dashboard to learn.
See our sales tax compliance services, check where you have obligations with the nexus calculator, or talk to us about Maryland.
Official sources
- https://www.marylandcomptroller.gov/content/dam/mdcomp/tax/legal-publications/tips/business/bustip10.pdf
- https://www.marylandcomptroller.gov/content/dam/mdcomp/tax/instructions/2024/SUT202-Instructions.pdf
- https://mgaleg.maryland.gov/mgawebsite/Laws/StatuteText?article=gtg§ion=13-601&enactments=false
- https://mgaleg.maryland.gov/mgawebsite/Laws/StatuteText?article=gtg§ion=11-601&enactments=false
- https://interactive.marylandtaxes.gov/extranet/compliance/harequest/default.aspx
- https://services.marylandcomptroller.gov/taxes/en/setting-up-a-payment-plan?id=kb_article_view&sysparm_article=KB0010057
Reviewed by Paul le Roux, CA(SA). Sales Tax Compliance USA handles US sales tax registration, filing and remittance for cross-border and domestic ecommerce sellers as a fully managed service.
This page is general information for educational purposes and does not constitute legal or tax advice. Sales tax rules change and depend on your specific facts. Consult a qualified tax professional about your own position.