USPS Bi-Fold Self-Mailer Tabbing Rules: Exactly 2 Tabs on the Top Edge (DMM 201.3.14.4)

What’s the Correct Way to Tab a Bi-Fold Self-Mailer?

If you design or mail bi-fold self-mailers (one 8.5″ × 11″ sheet folded in half with no staples), you’ve probably heard conflicting advice at the post office. Some clerks insist you need “one tab on the leading edge and two on the top.” That is incorrect for a standard bi-fold with the fold at the bottom.

Official USPS Rules (Straight from the Domestic Mail Manual)

According to DMM 201.3.14.4a1 (current as of April 2026):

“To seal folded self-mailers that weigh up to 3 ounces created in bi-fold… with a final fold on the bottom … place two nonperforated tabs on the top edge, one within 1 inch from the leading edge and another within 1 inch from the trailing edge, or place one tab on the leading and another on the trailing edge, both placed within 1 inch from the top.”

Correct tab placement for your piece (fold at bottom, open edge at top):

• Option 1 (most common & recommended): Two tabs on the top open edge — one within 1″ of the right (leading) edge and one within 1″ of the left (trailing) edge.
• Option 2 (also allowed): One tab on the leading vertical edge and one on the trailing vertical edge, both within 1″ of the top.

Tab Size – 1″ or 1.5″?

Depends only on the finished weight of the sealed piece:

• ≤ 1 oz → minimum 1-inch wide tabs
• > 1 oz (up to 3 oz max) → minimum 1.5-inch wide tabs

Your 0.6 mm thickness is perfect for automation — weight is the only factor that changes tab size.

Recommended Supplies (High-Quality & Automation-Friendly)

Get translucent 1″ and 1.5″ wafer seals here from SuppliesForMailers.com — they’re crystal clear, strong adhesive, and USPS-approved for high-speed processing.

For larger runs, automate the tabbing with a professional tabber machine from AllForMailers.com.

Why Some Post Offices Give Wrong Advice

The “one on leading + two on top” rule applies to quarter-fold, newsprint, or multi-panel designs (DMM 201.3.14.4a2–a3). It does not apply to a simple bi-fold with the final fold at the bottom. Always quote the exact DMM section above — it usually ends the debate instantly.

Quick Checklist Before You Mail

• Fold at bottom, open edge at top
• Two non-perforated tabs on top edge (or sides within 1″ of top)
• Address panel on front, Intelligent Mail barcode clear zone clear
• Take 3–5 samples to your Business Mail Entry Unit for verification

Official Reference: USPS Domestic Mail Manual DMM 201.3.14.4 – Folded Self-Mailers

Bottom line: For your 5.5″ × 8.5″ bi-fold self-mailer, two tabs on the top edge is the correct, compliant method. Save this post — it’s your official reference the next time someone at the counter disagrees.

Questions about your exact paper stock or weight? Drop them in the comments and I’ll help you dial it in perfectly.