Where and how to pay Maryland state income tax
Maryland accepts state income tax payments through the Comptroller of Maryland's website, by mail, or through your bank's bill-pay system. The online portal at marylandtaxonline.com is the fastest route — you can pay by electronic check, debit card, or credit card the same day you submit. Payments made online before 11:59 p.m. Eastern Time are considered received that day.
If you mail a check, send it to the address printed on your tax return or notice. The postmark date is what counts, not the date the Comptroller receives it, so mail early if you're close to a deadline. Payments by mail typically take 7 to 10 business days to post to your account.
Your bank's bill-pay system works if your bank participates in the ACH network, which most do. You'll need the mailing address from your return and the amount you want to send. This method is free and usually takes 3 to 5 business days to clear.
Key Takeaways
- The Comptroller's website at marylandtaxonline.com lets you pay by card or electronic check and shows confirmation the same day.
- Mailed checks must be postmarked by the deadline date to count as on-time, even if they arrive later.
- Bank bill-pay is free and works for most banks, but takes 3 to 5 business days to process.
- If you owe and miss the deadline, you will owe interest and penalties starting the day after the deadline, so paying late is still better than not paying.
- Estimated tax payments use the same online portal and follow different due dates: April 15, June 15, September 15, and January 15.
Payment deadlines and what happens if you miss them
Maryland state income tax is due on the same date as federal tax — April 15 of the year after you earn the income. If April 15 falls on a weekend or holiday, the deadline moves to the next business day. You can request an extension to October 15, but this only delays filing your return; you still owe tax by April 15, and interest starts accruing on any unpaid amount.
If you pay after the deadline, the Comptroller charges interest at a rate set quarterly. As of 2024, the rate is 8 percent per year, calculated daily from the due date. You also owe a failure-to-pay penalty of 0.5 percent of the unpaid tax for each month or part of a month the tax remains unpaid, up to 25 percent total.
These penalties and interest stack on top of the tax itself. A $1,000 tax bill paid 60 days late will cost you roughly $1,013 to $1,020 depending on the exact dates. The longer you wait, the faster the cost grows.
Estimated tax payments and quarterly deadlines
If you're self-employed, own a business, or have income that isn't subject to withholding, Maryland requires you to make estimated tax payments four times a year. These are due April 15, June 15, September 15, and January 15. Each payment covers one quarter of your expected tax liability for the year.
You can pay estimated taxes through the same online portal as regular tax payments. The Comptroller's website has a worksheet to help you calculate what you owe each quarter, though many people use their accountant's estimate. If you underpay estimated tax, you may owe a penalty when you file your return, even if you're due a refund overall.
Missing an estimated payment deadline carries the same interest and penalty structure as missing the April 15 deadline. If you realize mid-year that your income will be higher or lower than expected, you can adjust your remaining quarterly payments — you don't have to wait until April to correct course.
Payment methods and what information you'll need
| Payment Method | What You Need | Processing Time | Cost |
|---|---|---|---|
| Online at marylandtaxonline.com | Social Security number, tax year, amount owed | Same day | Card: 2.5% fee. E-check: free. |
| Bank bill-pay | Comptroller's mailing address, amount, tax year | 3–5 business days | Free |
| Mail a check | Check, return address, tax year | 7–10 business days | Postage only |
| Phone (automated system) | Social Security number, amount, card or bank account | Same day | Card: 2.5% fee. E-check: free. |
When you pay online or by phone, have your Social Security number and the tax year ready. If you're paying for a business, you'll need the Federal Employer Identification Number (EIN) instead. The system will ask for the amount and your payment method.
For mailed payments, write your Social Security number and tax year on the check itself. Include a note with your return if you're paying for multiple years. The Comptroller's office processes mailed payments more slowly than online payments, so don't use this method if you're close to a deadline.
Paying taxes you owe from a prior year
If you owe tax from a previous year and haven't paid it, you can still pay through the same channels. The online portal lets you select which tax year you're paying for. Interest continues to accrue on unpaid prior-year tax, so paying sooner rather than later reduces what you ultimately owe.
If the Comptroller has already sent you a notice of assessment or a demand letter, follow the instructions on that letter. Some notices include a specific payment coupon or account number that speeds up posting. If you've received a notice and want to dispute the amount, you have the right to request a hearing, but you still owe interest on any amount that turns out to be correct.
If you can't pay the full amount at once, contact the Comptroller's office about a payment plan. Maryland offers installment agreements for tax owed, though you'll still owe interest on the unpaid balance. The terms depend on the amount and your circumstances.
What to do if you can't pay by the deadline
If you know you won't be able to pay by April 15, file your return anyway. Filing on time stops the failure-to-file penalty (which is steeper than the failure-to-pay penalty) and starts the clock on the amount you owe. Then pay as soon as you can.
You can also request a short-term extension of the payment deadline by contacting the Comptroller's office directly. These are granted on a case-by-case basis and are not automatic. Explain your situation and ask what documentation they need. Even if an extension is denied, paying a few days late is better than not paying at all — the penalty for late payment is much smaller than the penalty for non-payment.
If you owe a large amount and can't pay it in one lump sum, ask about a payment plan. The Comptroller can set up an installment agreement where you pay a portion each month. You'll still owe interest on the unpaid balance, but a plan keeps you in compliance and stops collection action.
Confirming your payment went through
When you pay online, you'll receive a confirmation number immediately. Write this down or print the confirmation page. The Comptroller's website also lets you check the status of your payment by logging in with your Social Security number and looking at your account history.
If you paid by mail or bank bill-pay, allow the full processing time before checking your account. Payments can take up to 10 business days to show up in the system. If more than 10 business days have passed and your payment still doesn't appear, contact the Comptroller's office with your check number or bank confirmation number.
Keep records of every payment you make — the confirmation number, date, amount, and method. If there's ever a dispute about whether you paid, these records are your proof.
Frequently Asked Questions
Can I pay my Maryland state taxes with a credit card?
Yes, but only through the online portal or phone system. Credit card payments carry a 2.5 percent fee, so a $1,000 payment costs $1,025. Debit cards and electronic checks don't have a fee, so those are cheaper options if you have them available.
What if I overpaid my taxes and am getting a refund?
The Comptroller will issue a refund automatically once your return is processed. Refunds typically arrive within 4 to 6 weeks if you filed electronically, or 8 to 12 weeks if you mailed a paper return. You can check the status of your refund on the Comptroller's website using your Social Security number.
Do I have to pay Maryland state tax if I live out of state but work in Maryland?
Yes, Maryland taxes income earned in the state regardless of where you live. You may be able to claim a credit on your home state's return for taxes paid to Maryland, but you still owe Maryland tax on Maryland-source income. Check with a tax professional about your specific situation.
What happens if I make a payment but don't include my Social Security number?
The payment will be received, but it may take longer to post to your account because the Comptroller has to match it manually. Always include your Social Security number on mailed checks and provide it when paying online or by phone. If you've already mailed a check without it, contact the Comptroller's office with the check number and amount so they can match it faster.
Can I pay my Maryland taxes through a payment app like Venmo or PayPal?
No. The only official payment methods are the Comptroller's website, phone system, bank bill-pay, and mail. Scams sometimes pose as official payment apps, so always go directly to marylandtaxonline.com or call the Comptroller's office to confirm the right way to pay.