Third-Party Contact
The IRS contacting other people to find or verify your contact information. It states what it discloses, for how long, and that you get a list.
Full Definition
Third-party contact is the IRS approaching other people — the LT40 notice names neighbours, banks, employers and employees as examples — to get or verify a taxpayer's contact information.
It is announced in advance. LT40 tells you the IRS intends to do it before it does.
Three things the IRS states on that notice bound it, and all three are narrower than the fear the letter produces.
What is disclosed: "We'll generally need to tell them limited information, such as your name. The law prevents us from disclosing any more information than is necessary to obtain or verify the information we need."
For how long: "We may continue for a period of one year from the date of the notice."
Whether you find out: "We'll send you a copy of the contact list once a year. If you don't receive a list, it means we didn't contact anyone who we're required to advise you of."
The trigger is usually mundane. The IRS reaches for third-party contact where it cannot reach the taxpayer, which is frequently an address it no longer has.
What to do next
If the reason the IRS cannot reach you is an old address, correcting it is the fastest way to end the contacts — and it is also what determines where every later notice, including any carrying a deadline, gets sent.
Sources
- Understanding your LT40 notice — Internal Revenue Service, retrieved 2026-08-21
Last reviewed 2026-08-21 by Tax Resolution Clarity editorial.
Sourced to primary IRS materials and editorially reviewed. Not reviewed by a tax professional. Not tax advice.
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Where to go next
The IRS publishes the rules this page describes. Your own notice governs your dates.