Best Flat Box Mailers in 2026

SHIPPING MADE SIMPLE - White corrugated boxes (25 pack). these white mailing boxes are 7”x 5” x 4” and perfect for shipping small gifts and fragile items.

QUALITY CORRUGATED CRUSH PROOF BOXES – Mailing boxes are manufactured with corrugated material that meets edge crush test (ect) and bursting test standards to ensure safe shipping of your items

PROUDLY MADE IN THE USA MAILING BOXES – Shipping boxes are proudly made in the usa and are sfi certified. we offer a variety of shipping box sizes to meet your needs

Strong durable 100% recycled large corrugated boxes are ideal for packing shipping and storing heavy items Double Wall construction provides greater protection and stacking strength

Sold in bundle quantities and shipped flat to save on shipping fees and storage space

Corrugated Standard Cube Box

MAILING BOXES: The mailer boxes are made of kraft corrugated cardboard, lightweight but sturdy, which is great for mailing small items

BUSINESS SUPPLIES: The shipping boxes are great for small business packaging or gift wrapping, especially decorate them with labels, stickers, ribbons

EASY FOLD: The corrugated boxes are easy to put together in seconds, the tuck top has two locking taps to close boxes and keeps secure

DURABLE CONSTRUCTION: Made of 100% recyclable kraft corrugated cardboard, professional-grade, single-walled corrugated mailers are strong and sturdy, ensure safe shipping of your items.

EASY TO ASSEMBLE: One-piece shipping boxes fold together in seconds, unfold the boxes and tape up the seams. Strong enough for packing and stay organized.

EASILY ORGANIZE AND IDENTIFY: Cardboard boxes are perfect for mailing, retail shipping, gift packing. White shipping boxes are easily labeled with stickers or writed directly on the box for contents identification.

Easy to Assemble: These shipping boxes are simple and quick to assemble without glue, staples, or tape. Please refer to the guidance in the images or video.

Crush Resistant: Compared with the traditional design, high-quality ECT-32 corrugated cardboard with slots makes the rectangular mailing boxes reliable and sturdy, and the standard 90°angles will protect items inside while delivery.

Widely Used: Recyclable 10x7x3 shipping boxes fit for mailing, packaging, and storing small and lightweight fragile items, such as books, CDs, T-shirts, hats, mugs, and so on, can meet most shipping carrier specifications.

Easy to Assemble: These small shipping boxes are assembled in seconds without tape, glue, or staples. Please refer to the guidance in the video or images.

Crush Resistant: Compared with the traditional design, high-quality corrugated cardboard with slots makes the rectangular mailing boxes RELIABLE AND STURDY, and the standard 90°angles will protect items inside while delivery.

Widely Used: Recyclable 12 x 9 x 4 shipping box fit for mailing, packaging, and storing small and lightweight fragile items, such as books, CDs, T-shirts, hats, mugs, and so on, can meet most shipping carrier specifications.

Set of 25 Boxes: There are 25 pack boxes on the package, stored flat inside a larger carton.

Quality Material: Single wall corrugated boxes are made of recyclable cardboard. It's sturdy and durable for daily use.

Easy to use: Mailing boxes can be assembles in seconds without any tapes or glue. 32 ECT grade fits for standard stacking.

Quality Material: Single wall corrugated boxes are made of recyclable cardboard. It's sturdy and durable for daily use.

Easy to Use: Mailing boxes can be assembles in seconds without any tapes or glue. 32 ECT grade fits for standard stacking.

Wide Usage: White cardboard boxes can be used for shipping, mailing or storage some small items. It is very suitable for your own label or DIY.

Materials: 100 percent recycled kraft corrugated mailer boxes

Quantity: One package includes 25 cardboard boxes of the same size. White shipping boxes are shipped flat in a larger carton to better protect them and save space

Easy to Use: Unfold the mailing boxes, put in your goods, tape up the seams with tape, you can pack in minutes

SIMPLE, EASY TO FOLD - These one piece fold top shipping boxes can be folded in seconds easily, and no tape, glue or staples needed.

CRUSH PROOF - cardboard deluxe literature mailers folding to provide double protection on front and sides, each horizon flip top folding box mailer is made from 200#/ECT-32-E white corrugated with lid, eco-friendly, super strong yet light-weight to save on postage and keep your items secure;

BOX SIZE - The INNER size of these white rectangular shipping boxes are 8.75 inch length by 6 inch width by 2 inch height, outer size is 9.25 by 6.06 by 2.06 inch, packed and shipped in flat to save your storage room;

MATERIAL: The shipping box is made of recyclable corrugated cardboard, which is lightweight but sturdy, ensure your stuff safety.

DIMENSION: The shipping boxes set includes 25 packs of the cardboard box. The size of this small moving box is 13” x 10” x 2”(L x W x H), suitable for packing or mailing those small and lightweight items.

Assembles in seconds without tape, glue, or staples.

Easy to Assemble: These cardboard shipping boxes are simple and quick to assemble WITHOUT GLUE, STAPLES OR TAPES. Please refer to the guidance in the images or video.

Crush Resistant: Compared with the traditional design, high-quality corrugated cardboard with slots makes the rectangular mailing boxes RELIABLE AND STURDY, and the standard 90°angles will protect items inside while delivery.

Widely Used: Recyclable 9 x 6 x 2 shipping box fit for mailing, packaging, and storing small and lightweight fragile items, such as books, CDs, T-shirts, hats, mugs, and so on, can meet most shipping carrier specifications.

MATERIAL: The shipping box is made of recyclable corrugated cardboard, which is lightweight but sturdy, ensure your stuff safety.

DIMENSION: The shipping boxes set includes 25 packs of the cardboard box. The size of this small moving box is 9” x 6” x 2”(L x W x H), suitable for packing or mailing those small and lightweight items.

Assembles in seconds without tape, glue, or staples.

Small Shipping Boxes: Available size 5.6x3.9x2.9 inches(L x W x H). External size: 6x4x3 inches. Package includes 20 PCS small mailing boxes.

Multipurpose boxes for packaging: It’s sturdy and durable for packing notecards, toy crayons, Beauty Skincare, soaps, ornaments, and DIY Patterns on the boxes’ surface.

Safer Protective Material: The ECT-32 grade 6x4x3 shipping boxes are made of recyclable corrugated cardboard that is softer than solid plastic during delivery.

Quality Park 6" x 8" photo document mailers are made of extra rigid fiberboard to protect large photos. Perfect for shipping and storage. Our photo envelopes have Redi-Strip self sealing closures for a fast, instant seal. Redi-Strip envelopes are the perfect mailroom update for concerns about surface germs in the workplace. Skip the yuck, stay safe and save time with every mailing. Plus, the peelable paper strips protect your adhesive from dust so envelopes last longer in storage. Bright white envelopes made from 24 pt recycled fiberboard make a clean and professional presentation. Ideal for sending family photos, wedding pictures and important documents. 25 per box.

Please don’t lick these envelopes; Quality Park Redi-Strip closures don’t require moisture—just peel and press for a safe, dry, sanitary seal

Peel-off strips protect adhesives from dust so your envelopes will last longer; stock up for bulk mail and special events

Innovative design secures and protects comics, TPB's, and manga digests

Lightweight high quality material resistant to impact from rough shipping

Assembled product fits into a USPS Flat Rate Legal Envelope

Bubble Mailer Alternative - Our sturdy Rigid Mailers provide extra protection for your items during shipping, moving, or even storage

Convenient Bulk Packaging - Get more for your money with our Bulk Envelope Mailers, perfect for large-scale business shipping or small businesses

Stay Flat Design - Thin, durable, and Flat Envelopes to keep your documents and photos flat and protected during transit.

DIMENSIONS: Inside dimensions measure 12-inches (length) x 9-inches (width) x 9-inches (height). Carton capacity is approximately 0.563 cubic feet.

APPLICATIONS: Aviditi Double Wall Corrugated Boxes are great for packing, shipping, moving and storing heavy-duty items.

TOP QUALITY: Heavy-duty, professional grade construction provides twice the protection of a standard carton. Boxes are easy to assemble, fold together in seconds and proudly made in the United States.

EASY USE: Crush resistant mailers fold to provide double walls of protection on front and sides.These one piece mailers fold together in seconds. No tape, Glue or staples needed.

BOX SIZE: Measures 6-inches length by 4-inches width by 1-inches heigh, Each corrugated mailer is manufactured from 32ect-B kraft corrugated. NOTE: Please check the box size before purchase, this is small box.

BUY NOW RISK FREE: If for any reason, you don't absolutely like it, just return it, and we'll refund every penny (or replace it, if there is a problem).

MATERIAL: 32 ECT grade The shipping box is made of recyclable corrugated cardboard. Corrugated Mailers are super strong yet light-weight to save on postage.

Dimension: The shipping boxes outer size are 11x9x3 inches. The inner size is 10.5x8.7x2.8.

Assembles in seconds No tape, glue or staples are needed. Crush resistant mailers fold to provide double walls of protection on the front and sides.

DIMENSIONS: Inside dimensions measure 9-inches (length) x 9-inches (width) x 9-inches (height). Carton capacity is approximately 0.422 cubic feet. Use this popular size cube box to package cylindrical, round or odd shaped products.

APPLICATIONS: Minimize the impact of UPS/FedEx dimensional weight pricing by eliminating empty space. To obtain the desired size, simply cut down to the pre-scored interval on the sides of the box. Great for packing, shipping, moving, and storage.

TOP QUALITY: Multi-Depth style cartons offer the benefits of having many box sizes in inventory without using up valuable storage space. These boxes are the industry standard and are proudly made in the United States

MEDIUM BOXES: The finished dimension is 10 5/8"L x 7 7/8"W x 1 7/8"H, and each cardboard box weighs 4.1 oz, which is ideal for packaging small business or as party favor boxes

GLOSSY BLUE: Blue evokes reliability and infinity, these gift boxes for presents in brilliant color help to establish the brand’s visual identity and leave a memorable first impression

STURDY MAILERS: Made of recyclable corrugated cardboard paper, lightweight yet sturdy, securely closed from all sides which provides substantial protection to your products and gifts

✻【INGENUITY CRAFTSMANSHIP, FINE WORKMANSHIP】:Shipping boxes are made of thickened cardboard, selected from good quality and high strength corrugated cardboard, which is stiffer than ordinary cartons by 30%. It is strong and durable, easy to pack, and shorten the packaging process. Meanwhile,Perfect in workmanship,good performance in protection, and reusable. The white appearance looks clean and tidy, ideal for gift packaging or shipping packaging.Present a beautiful "Thank You" sealing label.

❉【FINE CRASTSMANSHIP, GOOD MATERIAL, HIGH QUALITY】: We pay attention to every detail of the carton production. The support of 90° right-angle is stale and provides ultimate protection for fragile items. The folding line is clear and easy to use, making the packaging and delivery faster. It is neatly cut and flatly packed to save space, the slot is firmly clasped and not easy to loose, which can secure the packaging during transportation. Just have the shipping boxes escort your "baby".

✤【ANTI-IMPACT, COMPRESS RESISTANCT, STRONGER LOAD BEARING】: The assembly of the shipping boxes is very simple. It can be done in a few seconds without tape, glue or staples. The simple and effective design makes the assembly easy, convenient and fast. The shipping box is resistant to impact and pressure, which can reduce the wear and tear of the goods during transportation, and provide better protection. Corrugated paper is elastic and can play a certain buffering role in case of impact.

40 Pack Small Shipping Boxes Value Set: There are a total of 40 pack 6x6x6 shipping box, the perfect size for plush toy, perfume or cosmetics, and other small business packing.

Eco-friendly Recyclable Material: Our small shipping boxes made of durable light-weight corrugated cardboard. Whether it is used for transportation or storage, these mailing boxes could protect your items from damage.

Easy to Assemble: No more complicated assembly steps! These shipping boxes for small business are easy to folded and assembled seamlessly with tape in few seconds.

✅EASY TO FOLD: You can assemble in seconds WITHOUT TAPE, GLUE, OR STAPLES.

✅DIMENSION: Internal size: 8.6x5.9x1.9 inches shipping boxes, pack of 25, lightweight but sturdy, suitable for packing or mailing those small and lightweight items.

✅MATERIAL: Industry-standard construction, single wall corrugated boxes, made of durable kraft corrugated cartons that are recyclable and eco-friendly, can keep your stuff safe.

6-pack of wardrobe moving boxes with metal bar for hanging clothing

Sturdy corrugated cardboard boxes for packing and moving hanging shirts, pants, jackets, kids clothing

Boxes ship flat; metal cross-bars to support clothing are included

MAILING BOXES: The mailer boxes are made of kraft corrugated cardboard, lightweight but sturdy, which is great for mailing small items

BUSINESS SUPPLIES: The shipping boxes are great for small business packaging or gift wrapping, especially decorate them with labels, stickers, ribbons

EASY FOLD: The corrugated boxes are easy to put together in seconds, the tuck top has two locking taps to close boxes and keeps secure

DIMENSIONS: 24" Length x 24" Width x 7" Height Flat Corrugated Boxes, Pack of 10. Measurements refer to the inside dimensions. Each individual box weighs approximately 2.546 pounds.

APPLICATIONS: The smaller depths on these cartons provide an ideal fit for shallow products. These boxes are perfect for shipping apparel, books, picture frames, artwork, mirrors and clothing.

TOP QUALITY: Standard strength industrial Corrugated Boxes. These boxes are the industry standard. Proudly made in the USA!

Easy to assemble: The white shipping boxes can be folding up easily without tapes, glue, or staples.

Quality corrugated boxes: 11x8x2 inches mailer boxes are made of recyclable corrugated cardboard. Standard 90° angles and slot design make it more sturdy and durable for small business packaging.

Dimension: The outer sizes measure about 11(L)x8(W)x2(H) inches, but you should refer to the inner sizes, which will be slightly smaller.

Precise Cutting: Those black shipping boxes can be folded properly due to meticulous measure and design.

Sturdy Material: The fall-resistant boxes for packing small business are made of single-wall cardboard with black reinforced surface.

Easy to Folding: The samll shipping boxes can be easily assembled strictly by pre-crease lines without any glue and tapes.