A Guide to USPS Mailing Regulations and Compliance

The United States Postal Service (USPS) has strict regulations in place to ensure safe and efficient mail delivery.

The USPS requires that all mailpieces be properly addressed with the correct zip code, which can be found using the USPS Zip Code Lookup tool.

To avoid delays, it's essential to use the correct postage for your mailpiece, as specified in the USPS's postage rates and fees section.

The USPS also mandates that all mailpieces be properly prepared for mailing, including being securely closed and sealed.

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If you're planning to ship something domestically with USPS, there are certain restrictions to keep in mind. One of the key restrictions is the maximum weight you can ship using different USPS shipping carriers.

First Class Mail has a maximum weight of 13 oz (368 g), while Priority and Express services have a maximum weight of 70 lbs (31 kg). The same maximum weight applies to Parcel Select, Library Mail, Media Mail, and Standard Post.

When shipping internationally with USPS, there are certain items that are restricted, including cigars, lithium batteries, medicine or drugs, and medical devices. These items cannot be shipped using USPS international services.

USPS also has size restrictions for international shipping. For example, the maximum weight allowed for Priority Mail International is 70 lbs, while the maximum weight for Priority Mail International Flat Rate Envelope is 4 lbs.

Here's a summary of the maximum weights allowed for international shipping using different USPS services:

USPS has specific size restrictions for shipping packages. The maximum dimension for a large envelope or flat rate one is 15 x 12 x .75 inches.

If you're shipping via USPS, your parcel must be at least 3 x 6 x 1.4 inches thick.

USPS Media Mail is used for sending media and educational materials, which include books, video and sound recordings, and printed music.

However, not everything fits the guidelines as media: computer drives, video games, and digital drives are excluded.

USPS First Class mail has a weight restriction of 13 oz for large envelopes and parcels.

Here's a quick rundown of USPS International shipping size restrictions:

The maximum weight allowed for Priority Mail International Flat Rate Envelope is 4 lbs.

The United States Postal Service (USPS) offers various mail types and services to cater to different needs.

First-Class Mail is one of the most popular options, with a maximum weight limit of 13 ounces.

The USPS also offers Priority Mail, which provides faster delivery at a higher cost.

Flat Rate Mail is a cost-effective way to ship packages, with a maximum weight of 70 pounds per box.

You can ship a wide range of items with flat rate mail, but there are some restrictions to be aware of.

Corrosive items, flammable materials, explosives, hazardous materials, and toxic items are either restricted or prohibited from being shipped with flat rate mail.

This is a good option for shipping non-hazardous items that are heavy, as it can save you money on postage costs.

First-Class Mail is an affordable way to send lightweight material anywhere.

The major restriction in terms of First Class mail is that maximum weight for large envelopes and parcels must be 13 oz.

You can send lightweight material, but keep in mind that anything over 13 oz will require a different type of mail service.

First-Class Mail is a great option for sending small packages and letters.

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Incorporating WooCommerce stores into your shipping process can be a bit tricky, but it's definitely doable.

You can easily list the restricted items and classify them into certain categories using the USPS shipping plugin. This allows you to separate them from the rest of the items to be packed.

You can also label them individually while shipping using the Package Settings and Label Generation Settings in the plugin. This makes shipping more efficient.

The package settings in the plugin let you pack the items in individual boxes as per your choice. This is a great feature for store owners who want to customize their shipping process.

You can set the packaging settings to pack items individually, making it easier to ship restricted items.

USPS mailing regulations can be complex, but understanding the basics can help you avoid delays and ensure safe delivery.

Some items are outright prohibited by USPS, including airbags, explosives, and marijuana for medical or non-medical purposes.

USPS also has restrictions on shipping liquids, which can only be sent if they're sealed in a waterproof container and packed properly to prevent damage to other items.

To ship liquids safely, use strong sealed outer packing for friction-top closure containers, and ensure containers can be sealed properly with screw caps or soldering clips. Glass containers must hold 4 ounces or less, while unbreakable containers can hold a minimum of 32 ounces, as long as they're cushioned, well-sealed, and in a waterproof container.

Here are some specific guidelines for shipping liquids:

USPS also has specific regulations for shipping hazardous materials, which must be securely packed with required labels and markings.

USPS has a list of items that are not allowed to be shipped via their service. These include airbags, explosives, ammunition, gasoline, and marijuana for medical or personal use.

Some items are restricted for international shipping, such as aerosols, fresh fruits and vegetables, and perfumes containing alcohol.

Other items that are prohibited for international shipping include cigarettes, dry ice, and nail polish.

Here's a list of prohibited items for USPS shipping:

International shipping restrictions also apply to the following items:

USPS has specific guidelines for shipping hazardous materials, outlined in Publication 52, which you can find on their website.

You'll need to comply with U.S. law and USPS guidelines, and ship items securely with required labels and markings.

USPS classifies certain materials as hazardous, so make sure to check their list for more detailed information.

To minimize risks, hazardous materials must be packed in sturdy, leak-proof containers.

The packaging must also be labeled clearly with the appropriate hazard class symbols and any other relevant information.

For international shipments, you'll need to comply with specific international packaging standards, which can be found in the International Mail Manuals (IMM) for the destination country.

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If you're shipping liquids, make sure to use containers that can be sealed properly, such as those with screw caps or soldering clips.

For glass containers, the fluid ounces should be no more than 4 ounces, and for unbreakable containers, the minimum is 32 ounces, cushioned, well-sealed, and in a waterproof container with strong outer packing.

Here are some specific requirements for shipping hazardous materials:

Failure to comply with regulations can result in severe penalties, including fines and imprisonment.

The costs of any cleanup associated with each violation can be substantial.

You may face a civil penalty of at least $250, but not more than $100,000 per violation.

Criminal penalties are also possible for knowingly mailing items or materials that are dangerous or injurious to life, health, or property.

Shipping internationally requires compliance with USPS International Shipping regulations, as well as regulations by the destination country.

You need to comply with every regulation before sending anything internationally.

The weight of packages may be restricted by country, with varying limits.

USPS cannot ship to countries under the OFAC sanction list, as selling to these countries is a violation.

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International shipping has its own set of rules and regulations. You'll want to make sure you're aware of the items with international USPS shipping restrictions, which include cigars, lithium batteries, medicine or drugs, and medical devices.

Cigars and lithium batteries are two items that are commonly shipped internationally, but it's essential to check the restrictions before sending them. Medicine or drugs and medical devices also have specific regulations, so be sure to research the requirements for your destination country.

The size restrictions for USPS international shipping vary depending on the service you choose. Here's a quick rundown of the maximum weights allowed for different services:

It's also important to note that international shipments may need to comply with specific international packaging standards. Consult the International Mail Manuals (IMM) for the destination country to understand the specific mailing conditions and ensure compliance.

For more insights, see: Priority Mail International Tracking

Bulk mail is a term used by the USPS to define quantities of mail sufficient to earn a bulk discount. It costs the USPS less money to process and deliver bulk mail when it's presorted by ZIP Code and they pass those savings on to mailers who do the work of presorting for them.

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To qualify for bulk mail, you need to meet the minimums for whichever type of mail you want to send, ranging from 50 pieces for Parcel Post to 500 pieces for Presorted First-Class Mail and several other types.

You'll need to apply for a USPS bulk mail permit and pay the associated fees, which currently cost $245.00 annually. If you're using Imprint Stamps, you'll also need to pay a Permit Imprint fee.

To presort your mail, you'll need to sort it into specific mail trays or mail sacks, fill out a postage statement, and apply barcoded labels to each mailing container. You'll also need to deliver the sorted mail to the Post Office that issued your permit.

Here are the minimums for bulk mail:

A presort service provider can commingle your mail with multiple client mailings to ensure everyone meets the volumes needed to qualify for the deepest postal discounts available. This can be a great strategy for earning USPS discounts without sacrificing time or resources.

You'll need to use Extra Service Code (ESC) 857 for all shipments containing hazardous materials, regardless of the destination.

If you're shipping to APO/FPO/DPO destinations, you'll need to use additional codes for packages containing radioactive material, lithium batteries, or Division 6.2 hazardous materials.

The USPS has added 20 new ESCs that identify specific types of hazardous materials, including lithium batteries. These codes are optional for now, but will be mandatory for domestic transportation in the future.

Here are some examples of material-specific ESCs:

Additionally, you'll need to use specific ESCs for lithium battery shipments, such as 816 for marked packages or 820 for unmarked packages.

APO/FPO is a special service that allows you to ship packages to military base locations. USPS lets you use Priority Mail APO/FPO flat rate boxes for this purpose.

These flat rate boxes can be a convenient option, as they offer a flat rate for shipping. However, there's a restriction on the weight of packages when using APO/FPO large flat rate boxes - they can only weigh less than 70 pounds.

USPS has made it relatively easy to ship to military bases with these special boxes.

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Hazmat Service Codes are a crucial part of shipping hazardous materials with USPS. Mailers must use Extra Service Code (ESC) 857 for all shipments containing hazardous materials/dangerous goods.

The revised Publication 52 rules require the use of ESC 857 for domestic, international, and APO/FPO/DPO destinations. This includes shipments containing radioactive material, lithium batteries (in an unmarked package), or Division 6.2 hazardous materials (i.e., infectious substances).

Mailers sending to APO/FPO/DPO destinations are required to use one or more additional codes, such as those for radioactive material, lithium batteries, or Division 6.2 hazardous materials.

The list of ESCs includes 20 additional codes that identify specific types of hazardous materials. These codes are optional for now, but will be mandatory for domestic transportation in the future.

Here are some examples of material-specific ESCs:

Lithium battery shipments require specific ESCs, including:

In some cases, hazmat mailers will also be required to use additional service codes (STCs) that provide USPS with details about how to handle the package, such as whether a signature is required upon delivery.