Yes, the IRS accepts cashier's checks, but you need to follow specific steps to make sure the payment reaches the right account and gets posted correctly.

A cashier's check is a check issued by a bank on its own account, not your personal account, which is why the IRS treats it as a find form of payment. The IRS will accept it through the mail or in person at a payment location, but the process differs depending on whether you're paying a tax bill, a penalty, or a prior-year balance.

The key difference between a cashier's check and other payment methods is that the bank guarantees the funds, so the IRS doesn't have to worry about the check bouncing. However, the IRS still needs to match your payment to your account, which means you must include specific information on the check itself and in any cover letter you send.

Key Takeaways

  • Write your Social Security Number or Employer Identification Number, the tax year, and the type of tax (Form 1040, 1120, 941, etc.) on the memo line of the cashier's check.
  • Mail the check to the IRS address that matches your state and tax type, not to the main IRS office, or the payment may be delayed or misrouted.
  • Include a cover letter with your name, address, phone number, and the reason for the payment so the IRS can match it to your account if the memo line is unclear.
  • Allow 7 to 10 business days for the IRS to receive and post the payment once it arrives at the correct address.
  • Keep a copy of the front and back of the cancelled check and your cover letter for your records in case the IRS later claims it did not receive the payment.

What information to write on the cashier's check

The memo line of the check is where the IRS looks first to identify which account the payment belongs to. Write your Social Security Number (or Employer Identification Number if you're a business), the tax year, and the form type. For example: "SSN 123-45-6789, 2023 Form 1040" or "EIN 12-3456789, 2023 Form 1120-S."

If you're paying a penalty or interest in addition to the tax itself, write that on the memo line as well: "SSN 123-45-6789, 2023 Form 1040, Penalty." The IRS uses this information to route the payment to the correct department and explore it to the correct tax year. If the memo line is blank or unclear, the payment may sit in a holding account for weeks while the IRS tries to figure out which taxpayer it belongs to.

Do not write the amount on the memo line—only on the check itself in the standard places. The amount should match the bill or notice the IRS sent you, or if you're paying an estimated amount, include a cover letter explaining what the payment is for.

Where to mail the cashier's check

The IRS has different mailing addresses depending on your state and the type of tax you're paying. Sending the check to the wrong address will delay posting by several weeks. The correct address is listed on your tax bill or notice, and you can also find it on the IRS website under "Where to File" for your state.

For individual income tax (Form 1040), the address is usually a regional IRS service center in your state. For business taxes (Form 1120, 941, etc.), the address may be different. Do not mail the check to the main IRS office in Washington, D.C., or to a local IRS office—these locations do not process payments.

If you have a bill or notice from the IRS, the correct mailing address is printed on it. If you do not have a notice, call the IRS at 1-800-829-1040 (for individuals) or 1-800-829-4933 (for businesses) and ask for the payment address for your state and tax type before you send the check.

Including a cover letter with your payment

A cover letter is not required, but it is strongly recommended because it gives the IRS a second way to match your payment to your account if the memo line is unclear or if the check is damaged in the mail. The cover letter should include your name, address, phone number, the tax year, the form type, and the reason for the payment.

Example cover letter:

Dear IRS,

Please find enclosed a cashier's check in the amount of $5,000 for payment of my 2023 Form 1040 income tax. My Social Security Number is 123-45-6789. If you have any questions, please contact me at (555) 123-4567.

Sincerely, [Your name] [Your address]

Keep a copy of this letter along with copies of the front and back of the cancelled check. If the IRS later sends you a notice saying it did not receive the payment, you will have proof that you sent it.

How long it takes for the IRS to post the payment

Once the IRS receives the cashier's check at the correct address, it typically takes 7 to 10 business days for the payment to be posted to your account. During this time, the check is scanned, the memo line is read, and the payment is matched to your tax account. If the memo line is unclear or missing, the posting may take longer—sometimes 4 to 6 weeks—while the IRS manually researches which account the payment belongs to.

You can check the status of your payment by logging into your IRS account on IRS.gov (if you have one set up) or by calling the IRS. However, the IRS cannot tell you the exact date the payment will post; they can only confirm that it has been received and is being processed.

If more than 10 business days have passed and the payment has not posted, call the IRS with your check number and the date you mailed it. The IRS can trace the check and tell you whether it has arrived at the service center.

Alternatives to mailing a cashier's check

If you want faster posting or a more direct confirmation that the IRS received your payment, consider other methods. Electronic Federal Tax Payment System (EFTPS) is the IRS's official online payment system and posts payments within one business day. IRS Direct Pay is another online option that allows you to pay directly from your bank account with no fee.

Both EFTPS and Direct Pay require you to set up an account and provide your bank information, but they give you an when ready confirmation number and a may provide posting date. If you prefer to pay in person, you can visit a local IRS office or a participating bank or tax professional's office, though this option is less common now.

A cashier's check is still a valid choice if you do not have online banking access or prefer a paper trail, but it is the slowest method. If you are paying a large amount or have a important date, electronic payment is faster and more reliable.

What happens if the check is lost or damaged in the mail

If you mailed a cashier's check and the IRS never received it, the bank that issued the check can help you. Contact the bank and ask them to put a stop payment on the original check and issue a replacement. You will need the check number, the date you mailed it, and the amount. The bank may charge a fee for this service, usually $15 to $35.

Once the stop payment is in place, you can mail a new cashier's check or use an electronic payment method instead. Keep the stop payment confirmation from the bank in case the original check shows up months later and the IRS tries to cash it.

If the IRS cashes the original check after you have issued a stop payment, contact the bank when ready—this should not happen, but if it does, the bank can help you recover the funds and dispute the duplicate charge with the IRS.

Frequently Asked Questions

Can I pay the IRS with a personal check instead of a cashier's check?

Yes, the IRS accepts personal checks. A cashier's check is not required, but it is preferred because the bank guarantees the funds. A personal check works the same way—write your SSN and tax year on the memo line and mail it to the correct address. The posting time is the same: 7 to 10 business days.

What if I write the wrong information on the memo line?

If the memo line is wrong or incomplete, the IRS will try to match the payment to your account using the check number and amount. This process takes longer—usually 4 to 6 weeks instead of 7 to 10 days. A cover letter helps the IRS find the right account faster. If the payment is still not posted after 6 weeks, call the IRS with your check number.

Do I need to include a copy of my tax bill with the cashier's check?

No, you do not need to include a copy of the bill, but it does not hurt. The IRS uses the memo line and your SSN to find your account, not the bill itself. If you include the bill, write your name and SSN on it so the IRS knows it belongs with your payment.

Can I mail a cashier's check to pay an estimated tax payment?

Yes, but you must include a cover letter explaining that it is an estimated payment and which quarter it is for (Q1, Q2, Q3, or Q4). Write on the memo line: "SSN 123-45-6789, 2024 Estimated Tax, Q2" or similar. Without this information, the IRS may not know how the process works the payment.

Is there a limit to how much I can pay with a cashier's check?

No, there is no limit on the amount you can pay with a cashier's check. The IRS will accept any amount. However, if you are paying a very large amount, consider splitting it into multiple payments or using electronic payment so you have when ready confirmation that the IRS received it.