The certified mail checklist, in order

The thirty-day clock in Section 1681i starts on the day the bureau receives your letter. Not the day you mail it. Everything below exists to prove that one date.

My mother mailed the church's tax filing certified every year and wrote the green-card date on the flap of the copy in pencil. She wasn't paranoid. She was right.

Before the counter

1. One letter per item per company. A letter with six disputes gets a form response. Six letters get six investigations.
2. Copy the letter and every attachment. The copy goes in the folder before the original goes in the envelope.
3. Use the dispute address on the bureau's current report or its CFPB entry — not the general P.O. box. A furnisher direct dispute goes to the address it designates for disputes, which Regulation V requires you to use.

At the counter

4. Certified mail, return receipt. Green card or electronic; either is admissible. Write the item on the receipt slip before you leave the window.

After

5. Log it. Date mailed, tracking number, item, company — one line in the tracker.
6. When the card comes back, write the receipt date in the tracker and count thirty days. That's the date the results letter is due by, plus five business days.

Which means: if a bureau says it never received your dispute, you have a signature that says it did, and the statute's clock started on that signature.

Step one, before Friday: buy the envelopes and print two copies of every letter. The counter is Monday.