USPS First-Class Mail Letter (FCML) shipping for sellers

USPS First-Class Mail Letter (FCML), also known as plain white envelope (PWE), is an optional shipping service that U.S. sellers can turn on for eligible card and sticker orders. It lets sellers ship in a standard paper envelope instead of a package.

FCML works best for lightweight, lower-value shipments that don’t require full USPS tracking. Many sellers use it to lower shipping costs for buyers and simplify fulfillment for inexpensive singles.

FCML may be a good fit if you:

• Regularly ship low-cost cards or stickers
• Want lower shipping costs for buyers
• Use flexible paper envelopes

FCML may not be the best fit if you:

• Ship higher-value items
• Need detailed USPS tracking
• Use bulky or rigid packaging

After you turn on FCML for a show, Whatnot automatically applies FCML to eligible shipments and upgrades shipments that no longer qualify.

On this page: 

• Which shipments qualify for FCML
• FCML shipping label pricing
• How to turn on FCML
  • Turn FCML on for future shows
  • Enable FCML for a scheduled show
• FCML envelope requirements
• Confirm drop-off for FCML shipments
• FCML delivery time and tracking
• FCML payout timing
• When FCML shipments are upgraded
• FAQs

Which shipments qualify for FCML

Once FCML is enabled for your show, Whatnot automatically applies it to eligible shipments.

Shipments qualify only if they meet all of the requirements below.

Your items must:

• Be sold in the Trading Card Games, Sports Cards, or Stickers categories
• Be sold during a live show
• Not use a custom shipping profile or max bundle size

Your show must:

• Have FCML turned on before the show starts

The shipment must:

• Contain 5 or fewer items
• Weigh 3 oz or less total
• Have a total shipment value of $20 or less
• Ship to a buyer in the U.S. (domestic shipping only)

If a shipment no longer meets these requirements, Whatnot automatically upgrades it to a different service.

FCML shipping label pricing

FCML label pricing depends on the shipment weight.

As of July 13, 2025, FCML label prices on Whatnot are:

*Note: FCML shipping costs include the USPS label price plus a small operational fee that supports features like Smart Bundling. Whatnot partners with carriers to help provide competitive shipping rates to customers.

How to turn on FCML for your shows

You must turn on FCML before your show starts. Once enabled, FCML automatically applies to eligible shipments during that show.

Turn FCML on for future shows

You can enable FCML for future shows by updating your shipping settings in Seller Hub.

Enable FCML for a scheduled show

If you already scheduled a show, you can turn on FCML before the show starts. If the show is repeats, your changes will apply to future instances of that show. 

FCML envelope requirements

Because FCML uses USPS letter mail, your packaging needs to meet standard envelope requirements.

Your envelope must:

• Be between 5 and 11½ inches long
• Be between 3½ and 6⅛ inches wide
• Be no more than ¼ inch thick
• Have an even thickness with no lumps or bulky areas
• Bend easily and remain flexible during USPS processing
• Have an aspect ratio between 1.3 and 2.5 (length ÷ height)

Don’t use:

• Bubble mailers
• Rigid cardboard or stiff inserts that don't bend
• Plastic sleeves as outer packaging
• Clasps, strings, or buttons
• Uneven or bulky packaging

FCML shipments that don’t meet USPS letter requirements may be refused, returned, delayed, or charged additional postage.

Confirm drop-off for FCML shipments

Because FCML tracking is limited, confirming drop-off with the in-app scanner is the most reliable way to keep buyers informed and ensure your shipping activity is accurately reflected.

When you scan an FCML shipment at drop-off, you:

• Notify the buyer right away with a photo of their shipment
• Create proof of shipment, which can help if questions about fulfillment timing come up later
• Ensure your Average Ship Time accurately reflects how quickly you ship

If you don’t confirm drop-off, FCML shipments may temporarily appear Overdue in Seller Hub. This status automatically updates to Shipped seven days after label creation if no scan is detected, but this isn’t considered proof of shipment.

How to scan FCML shipments

You can use the in-app scanner and Whatnot manifest (in limited-release) to confirm drop-off.

Before scanning, make sure:

• You have the correct envelope
• The label is clearly visible
• The image on your screen is clear and readable
• You’re comfortable with the image being shared with the buyer

When scanning:

Scan the entire envelope — not just the QR code.
The scanner needs to capture the buyer’s username in order to match it to their shipment and be considered “Shipped”. If multiple shipments exist for a buyer, you’ll be prompted to select the correct one.

If the envelope doesn’t scan automatically, use the shutter button.
Keep the scanner open. After a few seconds without a successful scan, a camera shutter button will appear. Tap it to manually capture a photo and match it to the correct shipment.

How this impacts your performance 

Sellers are expected to ship orders within 2 business days of the sale to provide a great buyer experience. 

Scanning FCML shipments at drop-off ensures your Average Ship Time reflects when you actually shipped your order, giving buyers a clearer view of your fulfillment speed.

If there’s no proof of shipment and a buyer reports a late delivery that’s escalated to Whatnot Support, the order may be cancelled and refunded.

Learn more about our Shipping Policy for Sellers.

FCML delivery time and tracking 

First-Class Mail Letter (FCML) is a slower shipping option. Orders usually arrive within 2 to 10 business days, depending on USPS processing and shipping distance. 

Tracking is limited and only available within Whatnot order details. It won’t appear on the USPS website.

You may see up to three tracking updates, including:

• In transit: Accepted by USPS
• Origin processing: Scanned at a USPS facility
• Delivered: Marked as delivered

Tracking updates can take 24–72 hours to first appear on Whatnot after drop-off.

Some shipments may not receive tracking updates at all. This can happen if the envelope is too thick, the barcode is damaged, or USPS sorts the envelope manually.

FCML payout timing

Because FCML has limited tracking, payout timing is based on label generation instead of relying on delivery scans:

• Standard payout: Earnings start processing 10 days after label creation.
• Early Payout: Earnings begin processing immediately after you generate the label. 

Once your earnings are available in your account balance, you can start a payout.

When FCML shipments are upgraded

FCML works best for flat, lightweight shipments under $20, but not every shipment qualifies. 

If a shipment becomes too heavy or too valuable, Whatnot automatically upgrades it to a different shipping service before generate the label. 

Here’s how upgrades work:

FAQs

Can I turn on FCML after a sale?

No. FCML must be enabled before your show starts. When turned on, it’ll automatically apply to eligible shipments sold during that show. 

Can I switch from FCML to another shipping method after a sale? 

Yes. You can upgrade the shipment by adjusting the shipment and increasing the package weight to 4 oz or more. This should change the service to Ground Advantage.

These upgrades count toward your weekly free shipping adjustment allowance. Additional fees may apply after you use your free adjustment allowance. 

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 exploring if this shipping option can be expanded to other categories in the future.