How to spot a fake IRS letter and what to do about it?

In 2024, the IRS reported that fake tax-related phishing schemes increased by 60% compared to previous years. According to the Treasury Inspector General for Tax Administration (TIGTA), over 1 million Americans received threatening IRS impersonation calls or letters, with reported losses exceeding $29 million.

But here's what scares more than the numbers: it's the sophistication. Last year, a tech founder in San Francisco received an official-looking letter claiming he owed $87,000 in back taxes. The letter had his company EIN, the correct IRS office address, and a legitimate-looking notice number. It threatened immediate asset seizure if he didn't respond within 10 days.

He called the number on the letter. A voice that sounded professional and authoritative confirmed the debt. He was one wire transfer away from losing $87,000.

Then he stopped. Something felt off. He hung up and called the IRS directly using the number from their official website. The real IRS had no record of any notice to his company. The letter was fake. The call was a scam. He'd almost fallen for it.

This same scenario is happening dozens of times every week to founders, small business owners, and accountants across the country. And according to the IRS's own data, many people don't stop. They panic, they pay, and then they realize too late what happened.

The IRS sends about 100 million pieces of mail annually. Criminals know this. They also know founders are paranoid about tax issues and will panic first, think second. That's the weapon they're using.

It's the details that separate a real IRS letter from a con, and the playbook for what to actually do if you get one.

Why fake IRS letters target startups?

Startups are perfect victims for IRS scams. Here's why:

First, you're likely young and less familiar with what official IRS mail actually looks like. You didn't get dozens of IRS letters when you were 25. You're getting your first one now, and you don't have muscle memory for what's real.

Second, you're paranoid about taxes. You know you're supposed to be doing something. You're not sure if you're doing it right. A letter saying you owe money lands and your brain immediately goes into crisis mode. You stop thinking. You start reacting.

Third, you have money. Or access to it. Criminals know if you're a founder, you either have capital or you have credit or you have urgency to make problems go away. That makes you worth targeting.

Fourth, you're busy. You're not going to spend 20 minutes verifying a letter. You're going to panic, call someone, and maybe do what the letter says before checking if it's real.

The IRS knows this. The criminals know this. They're betting on your fear overriding your skepticism.

What do real IRS letters look like?

The IRS has specific formatting standards. They've been consistent for decades. If something doesn't match, it's probably fake.

Real IRS Letters Have These Elements

1. A clear notice number at the top

Real IRS letters start with a notice number like "CP2000" or "CP2501" or "1040-ES". This isn't random. Different notice numbers mean different things. A notice about a tax adjustment looks different from a notice about a deadline.

If the letter says "Official Notice" but doesn't have a specific number, that's a red flag.

2. Your Employer Identification Number (EIN), not your Social Security Number

For business correspondence, the IRS uses your EIN. They don't send official business correspondence to your personal SSN. If the letter addresses you by Social Security Number, it's almost certainly fake.

3. A clear address for the IRS office that sent it

Real IRS letters list a specific IRS office address. Not just "IRS," but "Internal Revenue Service, Austin TX 73301" or whatever your assigned office is. You can verify this address against the official IRS website.

4. Contact information with a phone number you can verify

Real IRS letters include a phone number you can call. But here's the trap: scammers include phone numbers too. The trick is that it's their phone number, not the IRS's. Before you call any number on a letter, hang up and look up the IRS phone number yourself. Call that number and ask if the letter is real.

Never call the number on the letter. Ever.

5. A date the letter was sent

Real IRS letters are dated. They also include a deadline (usually 30 days from the date). Fake letters sometimes have vague language like "immediately" or "within 10 days" without clarifying what day the letter was actually sent.

6. No grammar mistakes or strange formatting

The IRS is bureaucratic, but it's not sloppy. The letters are formal, grammatically correct, and consistently formatted. If you see typos, weird spacing, or strange punctuation, it's probably fake.

7. No requests to open attachments or download files

Real IRS letters never ask you to open an attachment in an email. The IRS doesn't send official correspondence via email. If someone claiming to be from the IRS emails you a letter with an attachment, delete it immediately. That's 100% a scam.

The specific scams targeting startups right now

Scam One: The "Immediate Payment" Letter

This letter arrives claiming you owe back taxes immediately. It sounds urgent. It threatens penalties and interest. It says the IRS will seize your business assets if you don't pay within 10 days.

Real IRS notices give you at least 30 days. Usually more. The IRS doesn't threaten immediate seizure. They have a process. It takes time. If a letter says you need to pay within 10 days or they're taking your business, it's fake.

Scam Two: The "Verification" Email

You get an email claiming to be from the IRS asking you to verify your business information. It includes a link. It says your business records are incomplete and you need to "verify your details" immediately.

The IRS doesn't send verification requests via email. They send them via mail. They don't ask you to click links. If you get an email like this, delete it. Don't click anything.

Scam Three: The "Unclaimed Refund" Letter

This one is sneakier. It says the IRS did an audit and found that you overpaid taxes. You have an unclaimed refund. To claim it, you need to verify your business information and provide banking details so the IRS can deposit the refund.

If this sounds too good to be true, it is. The IRS doesn't notify you of refunds this way. And they never ask for banking information to process refunds. If you're owed a refund, they already have your banking information from previous filings.

What to do if you get a suspicious letter

Step One: Don't panic

This is the hardest step but the most important. Scammers want you scared. When you're scared, you make mistakes. You call the number on the letter. You open the attachment. You send information you shouldn't send.

Take a breath. Put the letter down. Come back to it tomorrow.

Step Two: Verify the letter's details

Check the specific elements we discussed:

• Does it have a notice number?
• Does it use your EIN or SSN?
• Does it list a specific IRS office?
• Is the address real? (Look it up on IRS.gov)
• Is the letter dated?
• Does it avoid asking you to open attachments?

If more than one of these elements is missing or wrong, it's probably fake.

Step Three: Call the IRS directly

Don't call the number on the letter. Look up the official IRS number for your business: 1-800-829-1040. Or go to IRS.gov and find the correct phone number for your situation.

Call them. Tell them you received a letter and you want to verify it's real. They can confirm whether the IRS actually sent it. They can tell you the notice number and what it's about.

This takes 15 minutes on hold. It's worth it.

Step Four: Check IRS.gov

Log into your IRS account at IRS.gov if you have one. The IRS has an online portal where you can see notices they've actually sent to you. If there's a real notice, it will be in your account. If there's nothing there, the letter is fake.

Step Five: Report it

If the letter is fake, report it to the IRS. Go to IRS.gov/report and follow the instructions for reporting a phishing scam or fraudulent letter.

Also report it to the Federal Trade Commission at reportfraud.ftc.gov. They track scams and use the data to go after criminals.

What happens if you ignore a fake letter

Nothing. If you ignore a fake letter, nothing happens. The scammers go away. They move on to the next person.

The only risk is if you actually responded to the fake letter by sending them money or information. If you did that, you have a different problem.

If you sent money: Call your bank immediately. Dispute the charge if it was recent. The scammers aren't actually the IRS, so you can get your money back if you act fast.

If you sent personal information: Monitor your credit. Check your credit report annually (free at annualcreditreport.com). If someone tries to open accounts in your name, you'll catch it early.

If you sent banking information: Call your bank and tell them what happened. They can flag your account for suspicious activity. Change your passwords. Don't panic, but be vigilant.

Why this matters for your business

Fake IRS letters are designed to distract you. They're designed to make you panic and make a mistake. For a founder, a mistake here could mean sending money you don't have or delaying real work while you deal with the aftermath.

The time you spend verifying a fake letter is time you don't spend on product, sales, or hiring. That matters.

More importantly, scammers are betting that you won't verify. They're betting you'll panic and pay. The more founders who verify and don't pay, the more the scammers move on to easier targets.

The bottom line

Real IRS letters have specific formatting. They include notice numbers. They list IRS office addresses. They never ask you to open attachments or click links. They never demand immediate payment.

If you get a letter that doesn't have these elements, it's probably fake. Verify it. Don't panic. Call the IRS directly.

The IRS is intimidating enough without adding fake letters to the mix. Know what real looks like. Everything else is noise.

And if you do get a real notice from the IRS? Read it carefully. Get your accountant involved. But you don't need to panic. The IRS has a process. They follow rules. They're not going to seize your business in 10 days. That only happens in scam letters.

References & Official Resources

To report IRS scams:

• Treasury Inspector General for Tax Administration (TIGTA) IRS Impersonation Scam Reporting: https://www.irs.gov/report-irs-impersonators
• Federal Trade Commission (FTC) Fraud Report: https://reportfraud.ftc.gov
• Report phishing emails to: phishing@irs.gov

To verify IRS notices:

• Official IRS Scam Alerts: https://www.irs.gov/help/tax-scams
• IRS.gov Account Services: https://www.irs.gov/account
• IRS Main Phone Number: 1-800-829-1040

Related Data & Research:

• IRS "Dirty Dozen" Tax Scams (2025): https://www.irs.gov/newsroom/dirty-dozen
• Treasury Inspector General 2024 Report on Tax Fraud: https://www.treasury.gov/tigta
• Federal Trade Commission Imposter Scam Data: https://consumer.ftc.gov/irs-impersonators
• How to Spot a Fake IRS Letter (Bench Accounting): https://www.bench.co/blog/tax-tips/fake-irs-letter
• Know the Warning Signs of a Tax Scam (IRS.gov): https://www.irs.gov/newsroom/know-the-warning-signs-of-a-tax-scam