Terry Ritchie tweeted this earlier today. It tends to confirm fears about information sharing between agencies and how it may complicate things at the border. It would appear this exchange will happen only if an actual tax lien has been filed; I would suspect this won’t apply to the majority of us.
The IRS has established procedures to facilitate tax collection from taxpayers who live outside the United States. If a taxpayer has an unpaid tax liability and is subject to a resulting Notice of Federal Tax Lien, the IRS may submit identifying taxpayer information to the Treasury Enforcement Communications System (TECS), a database maintained by the Department of Homeland Security (DHS). The database allows the DHS to identify taxpayers with unpaid tax assessments who are traveling to the United States for business, employment, or personal reasons (Internal Revenue Manual (IRM) §5.1.12.26). As a result, taxpayers traveling to the United States with unpaid tax assessments increasingly are being detained at the border.
I got a letter in the mail from the IRS stating that a request for transcript of tax return could not be processed because of my address across the sea. So, I called to correct the address, corrected it and then later got another letter from the IRS stating that my non-US address still didn’t match their records, which is still the case today.