First-Class Envelopes

What is a First-Class Envelope?

USPS First-Class Envelope rates offer an affordable way to ship lightweight, flat items through standard paper business envelopes. Mercari offers First-Class Envelope prepaid shipping labels exclusively for Trading Cards with limited tracking through Mercari included directly on your Order Status page. Tracking information is not available on the USPS website.

How much does it cost?

First-Class Envelope rates are available up to 3 oz. See below for the 2023 rates:

Read more about shipping rates and fees on Mercari here.

What can I ship?

Mercari First-Class Envelope prepaid labels are currently only available for Trading Cards.

What trading card categories and subcategories qualify for First-Class Envelope rates?

Trading card games and other collectable cards

  • Electronics > Video Game Merchandise > Interactive Video Game Cards
  • Toys & collectibles > Trading Cards > Booster Packs
  • Toys & collectibles >Trading Cards > Other Trading Cards
  • Toys & collectibles > Trading Cards > Single Cards
  • Sports trading cards

  • Toys & collectibles > Trading Cards > Auto Racing Trading Cards
  • Toys & collectibles > Trading Cards > Baseball Trading Cards
  • Toys & collectibles > Trading Cards > Basketball Trading Cards
  • Toys & collectibles > Trading Cards > Boxing Trading Cards
  • Toys & collectibles > Trading Cards > Football Trading Cards
  • Toys & collectibles > Trading Cards > Hockey Trading Cards
  • Toys & collectibles > Trading Cards > Soccer Trading Cards
  • Toys & collectibles > Trading Cards > Wrestling Trading Cards
  • Toys & collectibles > Trading Cards > Other Sports Trading Cards
  • K-Pop Photo Cards

  • Toys & collectibles > Vintage & Antique Collectibles > Paper Collectibles
  • First-Class Envelopes for sellers

    How to list an eligible item with First-Class Envelope rates:

    1. Create a listing: Complete your item description as usual and select an eligible trading card subcategory

    2. Weigh your envelope: Enter the item’s full weight inside a proper envelope

    3. Select "First-Class Envelope": A First-Class Envelope rate will appear for eligible trading card subcategories

    Download the latest version of the Mercari app to try it out (iOS or Android ).

    Choosing an envelope

    When choosing an envelope, make sure it is a standard paper envelope or flat mailer that falls within the below measurement guidelines.


    • Weight: Up to 3oz

    • Length: Between 5 and 11 ½ inches

    • Width: Between 3 ½ and 6 ⅛ inches

    • Thickness: Up to ¼ inch with no lumps

    Envelopes must be proportional and have an aspect ratio (length divided by height) between 1.3 and 2.5. Measure before sending and make sure to stay within the accepted limits to avoid surcharges.


    All envelopes must be paper.
    USPS will not accept First-Class Envelopes that have clasps, strings, buttons or similar closure devices. Bubble mailers, cardboard packages, poly mailers or any packaging made of plastic material will not be accepted.


    When adhering your label to the envelope, ensure that the recipient address is parallel to the longest side. Envelopes that do not have the recipient address parallel to the longest side will be returned to the sender.

    #10 envelopes (7” x 4.5”) work best.

    Packing your envelope

    Wondering how many cards you can ship in one envelope? See examples below:

    Examples of what items can ship by weight and size:

    Always weigh and measure your envelope prior to shipment to avoid overweight or oversize charges.

    Ensuring your envelope has uniform thickness

    The maximum thickness allowed for a First-Class Envelope is up to ¼ inch. If your envelope or flat mailer is not uniformly thick or has bumps or bulges, it may be classified as a package, subject to additional postage fees and returned.

    How to measure envelope thickness:

    To meet the USPS thickness requirements, insert trading cards to ensure uniform thickness throughout the envelope and avoid overstuffing. Check the thickness of your envelope with the adhered label before sending it.

    How to measure:

    1. Use a ruler that measures in tenths of an inch

    2. Place your envelope on a flat surface and ensure it has even thickness throughout

    3. Measure the thickest point of your envelope to ensure it is under ¼ inch

    Packing cards to ensure uniform thickness:

    Place cards evenly on either side of the envelope. Use the diagram below to learn how best to place your cards inside an envelope.

    How are First-Class Envelopes processed?

    USPS uses machines to process all First-Class Envelopes. Each envelope is fed through rollers and scanned. It is important that envelopes are flexible and not too rigid for this process.

    Risk of Bending in Transit

    Due to how envelopes are processed, there is a risk of bending or curving in transit.

    How to protect cards while maintaining flexibility

    1. Use semi-rigid card sleeves: This will help ensure that the envelope maintains uniform thickness while protecting cards in transit.

    2. Use a flat mailer: A flat mailer may offer more protection than a standard envelope. When using a flat mailer, it must be flexible enough to wrap around a cup.

    3. Top loaders:Top loaders can offer another layer of protection. Be sure to only pack one card per top loader. Top loaders must be side by side in the envelope (do not stack).

    Tips on testing envelope flexibility

    To test the flexibility of an envelope, you can perform a bend test. Here are the steps:

    1. Place the envelope on the edge of a flat surface with the longest sides parallel to the edge

    2. Gently bend the envelope over the edge of the flat surface

    3. Measure how far the envelope can bend without showing signs of damage. A minimum of 90° flexibility is required.

    4. Straighten the envelope back out. Check for any signs of damage, such as creases or tears.

    If the envelope bends easily and returns to its original shape without any damage, it should be considered flexible enough to meet USPS requirements. However, if the envelope cannot bend more than 90° over the edge or shows signs of damage, it may not be considered flexible and could be subject to additional postage fees or processing as a package.

    Returned to Sender

    If your item is returned to you and meets the requirements for measurement, thickness and flexibility, please contact the Mercari Help Center right away for assistance.

    Shipping Protection

    Shipping Protection is included with all Mercari prepaid labels. First-Class Envelopes are covered up to $20 in Shipping Protection for Trading Cards. Graded trading cards are not eligible for Shipping Protection when shipped with a First-Class Envelope.

    Lost Claims

    For lost items, support requests must be filed when (all criteria must be met):

    • 30 or more days following the acceptance scan (first scan by the carrier after receipt/pickup of the package)

    • 7 or more days from the last scan as provided by the carrier

    • The transaction is still active

    Damaged in Transit

    For items damaged in transit, support requests must be filed within 3 calendar days from delivery date and the envelope must meet measurement, uniform thickness and flexibility and requirements.

    First-Class Envelopes for Buyers

    How to purchase an eligible item with a First-Class Envelope rate

    1. Shop for trading cards: The First-Class Envelope is only available for eligible trading card subcategories

    2. Look for a First-Class Envelope rate: During checkout, see if First-Class Envelope is the selected rate for your purchase.

    3. Complete checkout: You're done! Your item will arrive in 2-8 days with tracking as usual.

    If a seller doesn’t offer a First-Class Envelope rate, send them a message and ask if they will switch their shipping offering to Mercari’s prepaid label for First-Class Envelopes.

    Cost-effective rates in select categories

    For eligible items listed with First Class Envelopes, you’ll save on shipping for trading cards compared to standard First Class package rates.

    Transit time and tracking

    Transit time

    Once the seller has shipped your item, First-Class Envelopes take 2-8 days in transit.


    Where can I track my envelope?

    You can track your First-Class Envelope directly through Mercari. Limited tracking will appear as usual on your Order Status page. The final delivery scan will appear when the USPS carrier completes their route.

    Note: Limited tracking for First-Class Envelopes is only available directly on Mercari. You will not find tracking information on the USPS website.

    What does limited-tracking mean?

    First-class envelopes offer limited tracking, meaning tracking typically includes 3 to 5 status updates. Please note that time between each status scan takes more time than First-Class or Priority Mail Packages. Examples of tracking status updates below:

    Example A: Envelope with 3 status updates

    1. In transit - Envelope accepted by local USPS office

    2. Origin processing - Envelope accepted at USPS sorting facility

    3. Delivered - Envelope delivered to buyer’s mailbox

    Example B: Envelope with 5 status updates:

    1. In transit - Envelope accepted by local USPS office

    2. Origin processing - Envelope accepted at USPS sorting facility

    3. Destination processing - Envelope accepted at USPS sorting facility near destination zip code

    4. Out for delivery- Envelope departed destination processing facility for delivery.

    5. Delivered - Envelope delivered to buyer’s mailbox

    In some cases, envelopes are not tracked. This can happen if the barcode is smudged, torn, or otherwise damaged during handling or processing. To help prevent damage during processing, it is important to ensure your envelope meets all measurement, uniform thickness and flexibility requirements.

    Tracking limitations may also occur if a package is processed manually instead of through an automated sorting machine.

    It's also worth noting that there may be occasional delays or errors in the tracking information due to technical issues or system glitches.

    Why does tracking take more time?

    The exact time it takes for First-Class Envelopes to start tracking can vary depending on the volume of mail being processed, the location of the origin and destination facilities, and other factors. In general, you can expect to see tracking information for your envelope within 24-72 hours after it has been shipped.


    Marked delivered but not received

    What should I do if my item is marked ‘delivered’ but I haven’t received it yet?

    Sometimes envelopes are marked delivered before being placed in the buyer’s mailbox. If your envelope is marked delivered but you have not received it, we recommend the following steps:

  • Wait one day to see if your envelope is delivered correctly
  • Contact the seller to let them know you’re still awaiting delivery

  • If your item has not been delivered after one day, please contact the Mercari Help Center for support.

    Why are First-Class Envelopes marked ‘delivered’ prior to actual delivery?

    USPS uses automated systems to process and track bins of many First-Class Envelopes rather than individual envelopes. Envelopes will be marked as delivered once a USPS mail carrier finishes delivering their assigned route.

    Sometimes, envelopes can be preemptively marked as "delivered" before actual delivery. This can occur for various reasons, including human error or technical glitches.

    Received but not marked delivered

    What should I do if I receive my item but it is not marked delivered?

    If you have received the item but it hasn't been marked as delivered yet, we suggest completing the transaction by following these steps:

  • Go to the 'Order Status' page
  • Click on the 'Confirm as received' button

  • What if I cannot mark my item as received?

    If you received your item and would like to close the transaction, please contact the Mercari Help Center for support.

    More about Shipping