You can still mail a paper check or money order, but let’s be honest—it feels a bit like using a rotary phone in 2026. The IRS actually encourages electronic payments. Their Direct Pay system is free, secure, and you can schedule it while sipping your morning latte.
But if you’re a die-hard paper person, make your check payable to the United States Treasury. And please, please write your Social Security number, the tax year, and “Installment Agreement” in the memo line. The IRS is not a psychic; they need clues.
A cultural reference: Remember in Friends when Monica obsessively organizes her apartment? Channel that energy here. Neat handwriting, no stray marks. The IRS clerks are not Joey Tribbiani; they don’t forgive sloppy mistakes.
The Envelope Etiquette
Include the payment slip from your installment notice. It’s like a VIP pass—it helps them match your payment to your account. If you lost the slip, write your name and address on a plain piece of paper. Yes, it’s okay to be that person.
Use a standard #10 envelope. No glitter, no stickers, no scented stationery. The IRS is not your pen pal. They’re more like a strict librarian who tolerates no nonsense.
