A letter from the IRS office at 1040 Waverly Avenue in Holtsville, New York means the agency’s Brookhaven campus has something to tell you about your federal tax account, and there is almost certainly a deadline printed on it. The first thing to do with any letter from IRS Holtsville is find the notice number in the upper-right corner of the first page. That code — it starts with “CP” or “LTR” — tells you exactly what the IRS wants and how long you have to respond.1Internal Revenue Service. Understanding Your IRS Notice or Letter Everything else follows from that number.
First, Confirm the Letter Is Real
IRS impersonation scams are common, and some of them are good. A few quick checks will tell you whether what you’re holding is genuine.
Real IRS notices arrive by mail. The agency almost never initiates contact by phone, email, or text, and it will never demand payment by gift card, wire transfer, or cryptocurrency, or threaten immediate arrest. Every genuine notice carries a CP or LTR number you can look up on IRS.gov to see what it means. If anything about the letter feels off, call the IRS using a number from IRS.gov rather than one printed on the suspicious page, and don’t share personal information until you’re sure.
One specific category deserves attention. If the letter asks you to verify your identity — Letters 5071C, 4883C, or 5747C — follow the instructions in that specific letter rather than filing anything else. If no verification letter has arrived but you suspect someone used your Social Security number to file a return, or you got a notice about wages from an employer you never worked for, file Form 14039, the Identity Theft Affidavit.2Internal Revenue Service. When to File an Identity Theft Affidavit
What Your Notice Number Means
Holtsville handles a lot of correspondence, but a handful of notice types account for most of what gets mailed from there.
A CP14 is the most frequently issued IRS notice. It says you owe a balance after your return was processed and asks for payment within 21 days.3Taxpayer Advocate Service. Notice CP14 – Balance Due $5 or More, No Math Error The IRS isn’t disputing anything; it processed your return as filed and wants the money.
A CP2000 is different and tends to look more alarming. The IRS’s Automated Underreporter system matches the W-2s and 1099s that employers, banks, and brokerages reported against what you reported on your return. When the numbers don’t line up — unreported dividend income, a stock sale you forgot — the IRS proposes changes to your tax, with penalties and interest already calculated. You have 30 days to respond, or 60 days if you live outside the United States.4Internal Revenue Service. Topic No. 652, Notice of Underreported Income – CP2000 The proposed amount is often wrong because the IRS didn’t know your cost basis on the stock sale or didn’t see a legitimate offsetting item.
Other notices announce refund offsets (the IRS applied your refund to a past-due balance), request additional information on an amended return, or address a specific penalty. Whatever the subject, the notice number is the key — look it up and the IRS will tell you plainly what it expects.
If the letter includes penalties and interest, know that penalties can sometimes be removed and interest cannot. Penalty relief comes through two routes: first-time abatement, available if you have a clean compliance history for the three prior tax years, and reasonable cause, which requires showing that circumstances beyond your control — serious illness, natural disaster, death in the immediate family — prevented timely filing or payment.5Internal Revenue Service. Penalty Relief for Reasonable Cause Lack of money alone doesn’t qualify as reasonable cause, though combined with other facts it may contribute.
How to Respond
Read the whole letter, with particular attention to the sections headed “What you should do” and “If you agree/disagree.” The IRS is usually specific, and your response needs to match.
If You Agree
Sign and return the response form. Pay as much as you can by the deadline to stop penalties and interest from piling up. You can pay online through IRS Direct Pay, by phone through EFTPS, or by mailing a check to the address on the notice.
If You Disagree
Gather the documents that back up your position. For a CP2000 proposing unreported income, that might be a corrected 1099 from the issuer, brokerage statements showing cost basis, or records proving the income was already reported in a different line of your return. For disputed business deductions, you need contemporaneous records showing amount, date, business purpose, and business relationship.6Office of the Law Revision Counsel. 26 USC 274 – Disallowance of Certain Entertainment, Etc., Expenses Asserting that a deduction was legitimate, without documentation, won’t work.
Write a cover letter that references the notice number and your Social Security number. Address each item the IRS raised, point by point. If you’re disputing a penalty, this is where you assert reasonable cause and explain what happened. Attach copies of your supporting documents, never originals, and keep a complete duplicate of the whole package.
Where to Send It
Use the exact mailing address printed on your notice. Sending a response to the wrong IRS address can cost you weeks and push you past the deadline.
CP2000 responses routed through Holtsville can also be faxed to 877-477-9599.7Internal Revenue Service. Understanding Your CP2000 Series Notice Faxing is faster and gives you a transmission confirmation.
If you mail your response, send it via USPS Certified Mail with Return Receipt Requested. Under the mailbox rule, the postmark date counts as your filing date, so even if the IRS doesn’t open the envelope for weeks, you’re covered as long as you mailed it on time.8Office of the Law Revision Counsel. 26 USC 7502 – Timely Mailing Treated as Timely Filing and Paying The certified mail receipt is your proof later if the IRS claims your response never arrived.
If you can’t meet the deadline, call the number on the notice and ask for an extension before the deadline passes. Sending a late response without warning gives the IRS grounds to finalize its proposed changes automatically.
You can also check your IRS Online Account at IRS.gov to see your balance, payment history, and recent activity, and to view many notices digitally.9Internal Revenue Service. Online Account for Individuals Processing a mailed response can take 30 to 120 days or more, so the online account is useful for tracking what the IRS has actually recorded.
If You Owe but Can’t Pay in Full
Agreeing with the balance and not having the cash to clear it is a common situation. The IRS has formal arrangements for it, and getting into one early is what keeps the situation from escalating to liens and levies.
A short-term payment plan covers balances you can pay off within 180 days, with no setup fee whether you apply online, by phone, or by mail.10Internal Revenue Service. Payment Plans; Installment Agreements Interest and the failure-to-pay penalty keep accruing, so paying sooner saves money.
A long-term installment agreement spreads payments over monthly amounts. Setup fees vary based on how you apply and how you pay; applying online with direct debit is consistently the cheapest option, and low-income taxpayers who use direct debit have the setup fee waived entirely.
An Offer in Compromise lets you settle for less than the full amount if you can show that paying in full would create a genuine financial hardship or that there is doubt about what you actually owe. It requires Form 656, Form 433-A or 433-B for the financial disclosure, a $205 application fee, and an initial payment; low-income certification waives the fee and initial payment.11Internal Revenue Service. Offer in Compromise The IRS rejects most offers, which is why professional help tends to pay for itself here.
Currently Not Collectible status is for cases where paying anything at all would prevent you from covering basic living expenses. You document your income, expenses, and assets on Form 433-A, and the IRS pauses active collection while you’re in that status.12Internal Revenue Service. Currently Not Collectible Procedures Penalties and interest keep running, and the IRS reviews the case periodically to see if things have changed.
If You Disagree With the Final Decision
When the IRS finalizes a change you still disagree with, you have appeal rights, but the deadlines are strict and missing them can end your options.
You can request a conference with the IRS Independent Office of Appeals by filing a written protest within the time the letter specifies, usually 30 days. If the total disputed amount for each period is $25,000 or less, you can use the simplified Small Case Request on Form 12203 instead of a formal protest.13Internal Revenue Service. Preparing a Request for Appeals Send the protest to the IRS office listed on your letter, not directly to Appeals.
If the IRS sends a Notice of Intent to Levy, you have 30 days from the date you receive it to request a Collection Due Process hearing by filing Form 12153.14Internal Revenue Service. Collection Due Process (CDP) FAQs Requesting the hearing pauses collection while your case is reviewed. Miss the 30-day window and you can still request an “equivalent hearing,” but it won’t stop the levy from moving forward.
If the IRS issues a formal Notice of Deficiency, sometimes called a “90-day letter,” you have exactly 90 days from the mailing date to petition the U.S. Tax Court, or 150 days if the notice is addressed outside the United States.15United States Tax Court. Starting a Case The Tax Court cannot extend this deadline. Filing a petition lets you dispute the IRS’s determination without first paying the tax, which is why the 90-day clock matters so much. Once it runs out, the IRS assesses the full amount and your only route left is to pay and then sue for a refund in a different court.
What Happens If You Do Nothing
Ignoring the letter is the single most expensive choice. If you don’t respond to a CP2000 within the deadline, the IRS treats its proposed changes as correct and assesses the full tax, penalties, and interest automatically. From there the consequences escalate on a predictable schedule.
Follow-up notices demand payment. If those go unanswered, the IRS issues a Notice of Intent to Levy, which triggers its authority to seize wages, bank accounts, and other property.16Office of the Law Revision Counsel. 26 USC 6331 – Levy and Distraint The IRS can also file a federal tax lien, which damages your credit and your ability to sell or refinance property.
For larger debts the stakes rise. If your total unpaid federal tax debt, including penalties and interest, exceeds $66,000, the IRS can certify the debt to the State Department, which may deny or revoke your passport.17Internal Revenue Service. Revocation or Denial of Passport in Cases of Certain Unpaid Taxes That threshold is adjusted annually for inflation.
The IRS has 10 years from the date it assesses a tax to collect it through levy or court action.18Office of the Law Revision Counsel. 26 USC 6502 – Collection After Assessment Penalties and interest compound through that whole period. Responding now, even if you can’t pay in full, keeps the payment plans and settlement options available that disappear once enforcement starts.
Getting Help
You have the right to be represented before the IRS by a qualified professional.19Internal Revenue Service. Taxpayer Bill of Rights You authorize someone to act on your behalf by filing Form 2848, Power of Attorney and Declaration of Representative. The representative generally must be an attorney, CPA, or enrolled agent.20Internal Revenue Service. Instructions for Form 2848
If paying for help isn’t realistic, Low Income Taxpayer Clinics provide free or low-cost assistance to qualifying taxpayers. For 2026, a single individual with income at or below $39,900 in the 48 contiguous states generally qualifies, with higher thresholds for larger households — $82,500 for a family of four, for example.21Taxpayer Advocate Service. Low Income Taxpayer Clinics Clinics also help taxpayers who speak English as a second language.
The Taxpayer Advocate Service is a different kind of help, for cases where the IRS system itself is failing you — months of waiting with no resolution, or an IRS action creating immediate financial hardship. You request TAS assistance by filing Form 911.22Taxpayer Advocate Service. Submit a Request for Assistance It isn’t a substitute for normal IRS channels, but it’s a strong backstop when those channels break down.