Guide to USPS First-Class Mail Letter shipping

If you're a seller in the US, selling cards or stickers from live shows, USPS First-Class Mail Letter (FCML) can be a simple, affordable way to ship small orders in a standard envelope. No fancy packaging needed.

Also known as plain white envelope (PWE) shipping, this option helps keep costs low for you and your buyers.

On this page: 

• When to use FCML
• Why sellers use FCML
• How much FCML costs
• Turn on First-Class Mail Letter shipping
• FCML envelope requirements
• FCML shipping time and tracking 
• If your shipment doesn’t qualify for FCML 
• FAQs

When to use FCML

You can use FCML if:

• You're selling in Trading Card Games, Sports Cards, or Stickers categories 
• You're selling these items during a live show
• Your item isn’t listed using a custom shipping profile / max bundle size
• The shipment includes no more than 5 items/cards
• The total shipment weighs 3 oz or less
• The total shipment value is $20 or under
• The shipment is domestic (the buyer is located in the US)

Why sellers use FCML

• Cheaper shipping costs: Label prices start at $0.69.
• Easier to pack: Just use a standard paper business envelope and print the label from Whatnot.
• Faster to drop off: Just drop the envelope in any USPS mailbox and skip a trip to the post office. 

How much FCML costs

As of July 14, 2024, FCML labels prices are: 

The total shipping cost for FCML includes the label price listed above, plus a small fee to help cover the operational cost of features like Smart Bundling and Flat-Rate shipping. Whatnot will continue to invest in great product experiences and work with our carriers to get preferential rates for our customers. 

Turn on First-Class Mail Letter shipping

Turn FCML on for future shows

You can turn on FCML in your Seller Hub shipping settings. This will apply FCML to eligible orders on all future shows.

Note: You can only turn FCML on from your Seller Hub in the Whatnot app. 

Update FCML for a scheduled show

You can also enable FCML for an upcoming show you already scheduled. 

If it’s a recurring show, these changes will apply to all future instances of that show. 

FCML envelope requirements

When packing an FCML shipment, use a standard paper envelope or flat paper mailer that fits:

• Length: 5–11½ inches
• Width: 3½–6⅛ inches
• Thickness: ¼ inch max, with no lumps
• Proportional aspect ratio (length ÷ height): 1.3 to 2.5
  • Example: A 6.5 x 4.25" envelope is OK because the aspect ratio = 1.53

Don’t use: 

• Envelopes with clasps, strings, buttons
• Plastic, bubble mailers, cardboard or rigid packaging

Sticking to these guidelines helps avoid USPS surcharges or returned mail.

FCML shipping time and tracking 

First-Class Mail Letter shipments usually arrive in 2–10 business days, depending on USPS processing times and the buyer’s location.

Tracking is limited and only visible on Whatnot. You won’t see tracking updates on the USPS website.

You can check for tracking updates in the Order Status page on Whanot. Since FCML tracking is limited, you you may see up to 3 tracking updates, such as:

• In transit – Accepted by your local USPS office
• Processing – Scanned at a USPS sorting facility
• Delivered – Delivered to the buyer’s address

Tracking Updates can take 24–72 hours to appear. The time it takes to start tracking a FCML shipment can vary depending on the volume of mail being processed, the location of the origin and destination facilities, and other factors.

Sometimes FCML shipments aren’t tracked at all, especially if the envelope is too thick, the barcode gets damaged, or the envelope is processed manually instead of using an automated sorting machine. This doesn’t usually affect delivery. 

If your shipment doesn’t qualify for FCML 

If an order doesn’t meet FCML rules by the time you need to ship, Whatnot will automatically upgrade the shipment to USPS Ground Advantage or Priority Mail.

Here's how it works: 

FAQs

Can I manually change the shipping method after a sale?

Yes. To upgrade from First-Class Mail Letter to Ground Advantage or Priority Mail, edit the shipment details and increase the weight of the package to 4 oz or more.

This is helpful when a buyer wins a high-value card after initially qualifying for FCML (for example, a low starting bid ends up selling for more than $20). 

These upgrades count toward your weekly allowance of 5 free shipping adjustments. After that, fees may apply.

When will I get paid for FCML orders?

• If you're on standard payout: You’ll be paid 10 days after the order is marked as shipped.
• If you're on Early Payout: You’ll be paid out as soon as you generate the label.

Can I use FCML for other categories on Whatnot? 

FCML is only available for Trading Card Games, Sports Cards, and Stickers sold through live shows. We’re actively evaluating whether this shipping option can be expanded to other categories in the future.