How to 发送 a Letter or Postcard: Domestic

用美国邮政总局发送邮件很容易! 我们的 video will help you with most letters, cards, and postcards you send domestically (inside the U.S.),包括U.S. territories and military bases in the U.S. 和国外.

为 how to ship a package, see How to 发送 a Package: Domestic.

发送 邮件: Step-by-Step Instructions


Step 1: Choose Envelope or Postcard

信封 are for sending flat, flexible things, like letters, cards, checks, forms, and other paper goods. 只为一个人 $0.68一级邮件® 永远® 邮票, you can send 1 oz (about 4 sheets of regular, 8-1/2" x 11" paper in a rectangular envelope) to anywhere in the U.S.!


No. 10 envelope compared to the minimum and maximum envelope sizes

信封 must be rectangular and made of paper to qualify for letter prices. Your envelope can be a maximum of 11-1/2" long x 6-1/8" high. (一)标准编号. 10 envelope is 9-1/2" long x 4-1/8" high.) You can fold what you put in your envelope, but it needs to stay flat—no more than 1/4" thick.

If you want to send letter-sized papers without folding them, you can use a large envelope (called a "flat"); the postage for flats starts at $1.39. If your large envelope is nonrectangular, 刚性(不能弯曲), 或块状(不均匀厚), you'll have to pay the package price.

提示: If your envelope can't fit through 美国邮政总局 mail processing machines, 或者是刚性的, 块状的或有搭扣的, 字符串, 或按钮, it's "nonmachinable" and you'll have to pay $0.还有44个才能发送. (See additional postage in Step 3.) You'll also have to pay more if your envelopes are square or vertical (taller than they are wide).

明信片 are for short messages that you don't need to put in an envelope. 使用 $0.53明信片邮票 to send a standard-sized postcard anywhere in the U.S. Standard postcards are usually made of paper, are between 5" to 6" long and 3-1/2" to 4-1/4" high, 都在0之间.007"和0 ".016“厚.

大小 & Weight Requirements – 明信片 & 信封
信封及明信片 with return address written in the top left corner and delivery address in the bottom center.


信封: Write your address (the "return" or "sender" address) in the top left corner. Write the delivery address (the "recipient" address) in the bottom center.

明信片: 明信片 come in different formats, so write the delivery address in the space it gives you (on the same side you write your message and put the 邮票).


Print your return address and the delivery address clearly, 在正确的地方, to make sure your mail is delivered on time.


  • Print addresses neatly in capital letters.
  • 用钢笔或记号笔.
  • 不要使用逗号或句号.
  • 包括 ZIP + 4® 尽可能编写代码.


Write your address (the "return address") in the top-left corner. 包括 following on separate lines:

  • 你的全名或公司名称
  • 公寓或套房号码
  • 完整的街道地址
  • 城市,州和邮政编码+4


Write the delivery address (the "recipient" address) in the bottom center of the envelope. 包括 following on separate lines:

  • Recipient's full name or company name
  • 公寓或套房号码
  • 完整的街道地址
  • 城市,州和邮政编码+4
Advanced Tips for Secondary 地址 (like Apartment or Suite) 邮政地址标准

特殊的你.S. 地址


Some 波多黎各 addresses include an urbanization or community code for a specific area or development. 地址 with an urbanization code, abbreviated URB, should be written on 4 lines:

150 call a
圣胡安pr 00926-3232

More 波多黎各 Address Examples

U.S. 属维尔京群岛

属维尔京群岛 addresses have the same format as standard addresses. The right abbreviation for this territory is "VI," not "US VI" or "USA VI":

Kingshill vi 00850-9802

军事 and 外交邮件 (APO/FPO/DPO)

邮件 military and diplomatic addresses 被区别对待:

  • include the city or country name when you send something to an APO/FDO/DPO address in another country. This keeps your mail out of foreign mail networks.
  • Do include unit and box numbers if they're assigned:

Fpo ap 96691

More Details on 军事 地址

When you're done addressing your envelope, put what you're sending inside the envelope, then close and seal it (using the envelope's glue or tape).

信封及明信片, each with a 邮票 in the upper right corner

第三步:计算邮资(& Add 保险 or 额外十大网堵平台)

A 一流的邮件® “永远”邮票售价0美元.68 and goes in the upper right corner of the envelope. (你也可以 use any combination of 邮票s that adds up to $0.68.)

If your letter is heavier or bigger, or if you want to add insurance or extra 十大网堵平台s like 挂号信® 十大网堵平台,你会付更多的钱.

A standard postcard 邮票 costs $0.53. (Large or square postcards will cost more.) Put the postcard 邮票 in the space provided near the delivery address.


Postage for letters mostly depends on weight and size/shape. You can weigh your letter with a kitchen scale, 邮政规模, at a self-十大网堵平台 kiosk,或 the 邮局 计数器.

提示: 根据经验, you can send 1 oz (4 sheets of printer paper and a business-sized envelope) for 1 一流的邮件® 永远® 邮票(现时$0.68).

The postage for a large envelope (or flat) starts at $1.39 / 1盎司.


提示: If you're sending larger envelopes (flats) using 优先邮件® 或特快专递® 十大网堵平台,您可以使用 Click-N-Ship® 十大网堵平台 to pay for and print your own postage online.


If your envelope weighs over 1 oz, you can buy additional postage in the amount you need:

  • 每增加1盎司是0美元.24个字母,最多3个.5 oz and large envelopes up to 13 oz.
  • Nonmachinable物品, including envelopes that are lumpy or rigid, 或者有扣子, 字符串, 或者按钮将花费0美元.还有44个要送. You'll also have to pay more if your envelopes are square or vertical (taller than they are wide).
  • 你也可以 buy 1¢, 2¢, 3¢, 4¢, 5¢, and 10¢ 邮票s at 邮政商店.

提示: Put the 邮票 on last; that way, if you make a mistake at any other point, you won't waste a 邮票.



如果你想要保险, 送货证明, 签名十大网堵平台, 或其他可选十大网堵平台, 你得额外付费.

我们的 保险 & 额外十大网堵平台 page has more details; some of the more common add-on 十大网堵平台s for letters include:

  • 挂号信®: Get proof that you mailed your item and that the recipient signed for it.
  • 挂号邮件®: 美国邮政总局's most secure mail 十大网堵平台–mail is processed manually, handled separately and securely, and signed for along every step of its journey. The recipient must sign for the mail to confirm delivery (or attempted delivery).
  • Return Receipt: You'll get a printed or emailed delivery record showing the recipient's signature. You can combine Return Receipt with other 十大网堵平台s, 包括挂号邮件, 挂号邮件, 特快专递® 十大网堵平台,以及更多.
  • Adult Signature Required: Only an adult (age 21+) can sign for the mail after 出示有效的政府证件.
发送 your letter or postcard from your mailbox, a 蓝色收集箱, or 邮局.


Once your envelope or postcard has the correct addresses and postage, 你可以用几种方式发送, including putting it in your mailbox or dropping it in a 蓝色收集箱 或者是 邮局 位置.


  • Put your letter inside your mailbox and raise the flag (if you have one).
  • If you have a cluster mailbox, drop it in the outgoing mail slot.
  • Drop it off in a 蓝色收集箱.
  • Take it to a 邮局 lobby drop.

重要提示: If your envelope has postage 邮票s and weighs more than 10 oz or is thicker than 1/2", you can't put it in a collection box; you have to give it to an employee at a 邮局 位置. 更多详情请浏览 What Can and Cannot be Deposited in a Collection Box?

邮局 & 下降的位置
Animated image of mail moving at high speed on belts and around drums in an automated sorting machine.


The Postal Service uses 高速分拣机 to help process and deliver 425.3 million mail pieces each day. Here are some extra tips to improve your mail sending experience:

  • 保持灵活: Don't send rigid (hard) objects in paper envelopes.
  • 发送 embellished invitations (for weddings, graduations, etc.)? Get them hand-canceled or put them inside another envelope.
  • 需要跟踪? 了解你的选择.


Flexible and flat 项目 only (like paper or photos, less than 1/4 inch thick). Rigid or lumpy Items (like keys or flash drives) can tear your envelope.


明信片, letter envelopes, and large envelopes (flats) all need to 弯曲 以符合美国邮政总局的要求® 高速分拣机.

  • OK: Flexible, flat things like stickers, photos, trading cards, etc. should be okay—as long as your envelope stays flat, not lumpy, and less than 1/4" thick.
  • 不可以: Don't put rigid objects (like flash drives, coins, keys, hard plastic card cases, etc.) loose in unpadded paper envelopes: They could get torn out of the envelope, 堵塞分拣机, 造成延误, 或者甚至迷路.

而不是, for rigid and odd-shaped objects (or things you don't want to get bent), we recommend using a padded envelope or small box and 把它作为一个包裹寄出去.

Protect Special 信封: Using Wax Seals, String, or Ribbons? 把它放在另一个信封里.

发送 Embellished Invitations (for Weddings, Graduations, etc.)

If you want to send a specially decorated envelope (like some wedding invitations):

  • You can pay the extra fee for nonmachinable 一流的邮件® 项目, bring your mail to the 邮局™ 计数器, and ask the retail associate to hand-cancel your embellished invitations.
  • 外部装饰 invitations: If you use wax seals, 字符串s, ribbons, etc. on your envelopes, don't try to send them exposed. 而不是, to make sure your envelopes arrive looking the way your designer intended, put them inside another envelope.


跟踪 is not available for 一流的邮件 项目. If you'd like to get tracking information for your letter:

  • You can pay extra to send your letter using 特快专递® or 优先邮件® 十大网堵平台.
  • You can get delivery confirmation by adding 挂号信® 或挂号邮件® 十大网堵平台. (You can even combine it with Return Receipt if you want the recipient's signature.)