How Much Does It Cost to Mail a 9x12 Envelope?
First-Class Mail® service is an affordable and easy way to send envelopes and lightweight packages. First-Class Mail Forever® stamps cost $0.58 (the current 1 oz price) and will never expire, even if the First-Class™ postage rate goes up. For packages (up to 13 oz), prices start at $4.30.
Buy Stamps First-Class Mail Prices
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- Mail delivered in 1–5 business days
- Small packages delivered in 1–3 business days
- Best priced service for items up to 13 oz
- Insurance for loss or damage up to $5,000 for merchandise only
- Eligible for delivery confirmation services such as Certified Mail®
- One price for up to 3.5 ounces with commercially priced letters and cards
- Prices based on shape and weight
Standard Letter & Postcard Sizes See Insurance & Extra Services
- Standard-sized, rectangular envelope stamps start at $0.58.
- Square, oversized, or unusually shaped envelope stamps start at $0.88.
- Standard-sized, rectangular postcard stamps start at $0.40.
- Oversized postcards need letter stamps, which start at $0.58.
- Large envelopes (flats) start at $1.16.
- Small packages start at $4.30.
- Maximum weight for First-Class Mail letters is 3.5 oz; for large First-Class Mail envelopes and parcels, the maximum weight is 13 oz.
- All postcards and envelopes (or flats) must be rectangular, otherwise an additional charge may apply. Additional size restrictions apply depending on the type of mailpiece you're sending.
How to Send Letters & Postcards
Unusually shaped mail, like square or vertical envelopes, lumpy envelopes, rigid envelopes, and mail with clasps, string, buttons, must be hand-cancelled. They are charged a nonmachinable surcharge even if they weight less than 1 oz.
If a mailpiece exceeds the maximum length, height, or thickness, it will be charged at the next higher price and mailpiece category.
Large First-Class envelopes (flats) that exceed maximum dimensions, are rigid, non-rectangular, or not uniformly thick, are charged parcel prices.
The USPS® Price Calculator tool will show you how to measure your envelope and then calculate your domestic postage costs for you.
Calculate a Price
There are specific regulations and standards for mailing restricted, prohibited, and hazardous materials, including cigarettes and smokeless tobacco.
USPS understands what's most important to our business customers: speed, affordability, security, and customer service. We help businesses provide these services and resources to your customers at discounted rates.
First-Class Mail is targetable, trackable (with certain extra services), and measurable, offering a wide range of options for businesses. With address correction and forwarding services, your messages will reach a greater percentage of your target audience.
Bulk Discounts. First-Class Mail commercial pricing is available for presorted letters, flats, and packages with a minimum quantity of 500 mailpieces. Automation discounts may also apply.
Eligibility Requirements for Automation Discounts
One Price Up to 3.5 Ounces. Pay one price for up to 3.5 oz for First-Class Mail presort and automation compatible letters and cards. This is a cost-effective way for businesses to include promotional messages with bills, invoices, and statements. The one price for up to 3.5 oz rate is not a blended rate and does not apply First-Class Mail single-piece letters.
- Shipping for Business
- Business Price Calculator
- View Commercial Price List
- 3.5 Ounce Free Fact Sheet RTF (125 KB)
How Much Does It Cost to Mail a 9x12 Envelope?
Source: https://www.usps.com/ship/first-class-mail.htm