Mail from P.O. Box 13735, Philadelphia, PA 19101 typically comes from the Internal Revenue Service, which runs a processing campus in Philadelphia. That does not automatically mean the letter inside is legitimate. Before you pay anything, sign anything, or call any number printed in the letter, verify it against IRS records using the notice number in the upper-right corner.
Confirm the Letter Is Really From the IRS
Every genuine IRS notice carries a CP or LTR number in the upper-right corner of the first page.1Internal Revenue Service. Understanding Your IRS Notice or Letter Look up that number on irs.gov and you’ll find a plain-language explanation of what the notice means and what, if anything, you need to do.
A real notice will name a specific tax year, explain why the agency is writing to you, give you a deadline, and list a phone number for questions. It will not demand payment by gift card, prepaid debit card, wire transfer, or over social media. Any letter that does is a scam, whatever return address is on the envelope.2Internal Revenue Service. How Taxpayers Can Protect Themselves From Gift Card Scams
The strongest cross-check is your IRS Online Account. Log in and you can see digital copies of notices the agency has sent, your balance, and your payment history.3Internal Revenue Service. Online Account for Individuals If the letter in your hand doesn’t appear there, call the IRS using a number from irs.gov (not the letter) before you act.
What the Philadelphia Campus Handles
Philadelphia is one of seven IRS locations that issue CP2000 underreporter notices, which flag mismatches between what you reported on your return and what employers or financial institutions reported to the IRS.4Internal Revenue Service. Understanding Your CP2000 Series Notice If your letter is a CP2000, use only the response address and fax number printed on the notice itself.
The Philadelphia office is also the contact point for many international taxpayers dealing with individual account issues.5Internal Revenue Service. Contact My Local Office Internationally
One thing Philadelphia does not do: process standard Form 1040 filings. Individual income tax returns go to Austin, Charlotte, Kansas City, Louisville, or Ogden depending on where you live.6Internal Revenue Service. Where to File Addresses for Taxpayers and Tax Professionals Filing Form 1040 Estimated payments on Form 1040-ES go to Charlotte or Louisville.7Internal Revenue Service. Form 1040-ES Addresses for Taxpayers Living Within the 50 States Amended returns from Pennsylvania residents go to Kansas City.8Internal Revenue Service. Where to File Addresses for Taxpayers and Tax Professionals Filing Form 1040-X A Philadelphia return address on unsolicited mail claiming to be about your 1040 is worth extra scrutiny.
What to Do Once You’ve Verified It
Read the entire notice before you do anything else. Most IRS letters are not emergencies. They ask you to respond by a specific date, and that date is the part that matters. Ignore the notice and the IRS proceeds with whatever it proposed — an added assessment, an adjusted refund, or a move into collections.
If you agree with what the letter says, follow the payment or filing instructions on the notice. If you disagree, reply in writing by the deadline with supporting documents. Send your reply to the address printed on the notice itself, not the return address on the envelope, and use USPS Certified or Registered Mail so you have proof of the mailing date. Under Internal Revenue Code Section 7502, a timely postmark counts as timely filing even if delivery is delayed.9Internal Revenue Service. New U.S. Postal Service Rules Could Affect Whether Your Tax Filing Is Considered On Time
Keep copies of everything: the original notice, your response, the Certified Mail receipt, and any follow-up letters. A clean paper trail can resolve a repeat inquiry with one phone call instead of weeks of correspondence.
How Long the IRS Takes, and How Long It Has
Once you mail a response, expect roughly 60 days for the IRS to process it and update your account.10Internal Revenue Service. Held or Stopped Refunds Don’t send duplicate replies or call every week. The agency will either write back or update your Online Account when it’s done.
The IRS also can’t come after you forever. The agency generally has three years from the due date of the return (or the filing date, whichever is later) to assess additional tax. That stretches to six years if you underreported income by more than 25 percent, and there is no limit at all if you never filed or filed a fraudulent return.11Internal Revenue Service. 12Internal Revenue Service. Get Your Tax Records and Transcripts
Consider a tax professional if the notice proposes a large balance, spans multiple years, or relates to an audit. You can authorize someone to deal with the IRS for you by filing Form 2848, which grants power of attorney for specific tax matters and years.
If you’ve been trying to resolve an issue for more than 30 days past the normal processing time and getting nowhere, the Taxpayer Advocate Service can step in. TAS handles cases where IRS systems have broken down or where an unresolved tax matter is causing financial hardship. Call 1-877-777-4778 or submit Form 911, and expect about 30 days before an assigned advocate follows up.13Internal Revenue Service. Contact Us – Taxpayer Advocate Service
If You Want to Reply by FedEx or UPS
The Philadelphia campus is not on the IRS list of addresses that accept private delivery service shipments. Only three submission processing centers do: Austin, Kansas City, and Ogden.14Internal Revenue Service. Submission Processing Center Street Addresses for Private Delivery Service If a courier reply matters to you, check the notice for a street address; otherwise use USPS Certified Mail to the P.O. box printed on the letter.