USPS and Shippo FAQs

This covers common questions specific to USPS. For more general questions, see General Shippo FAQs.

To learn about common postal surcharges from the USPS please visit this article: Understanding Postal Surcharges in Shippo

Using your own USPS account

Shippo saves you up to 90% off retail USPS rates through our USPS carrier account. Check out our USPS Shipping Calculator to get an idea of the savings you'll see. These rates are available automatically to all Shippo users immediately upon sign-up.

Can I use my own USPS account in Shippo?

Shippo saves you up to 90% off retail USPS rates through our USPS carrier account, available automatically to every Shippo user immediately upon sign-up. Check out our USPS Shipping Calculator to see the savings for yourself.

If you have your own negotiated rates with USPS you'd like Shippo to host, contact our Support Team and we'll route your request to the right team.

Tracking, labels, and pricing

Do all USPS labels have tracking numbers?

Yes. Every USPS service level available in Shippo includes tracking, and USPS assigns a tracking number when you create the label. See "Tracking Packages" for more.

Why was my USPS package marked as unpaid or fraudulent?

USPS sometimes flags packages as "unpaid" or "fraudulent" when their barcode can't be scanned easily. To help prevent this:

• Print your shipping label at a high quality setting. Blurry, light, or low-contrast prints are hard for USPS scanners to read reliably.
• Place the barcode on a flat, smooth part of the package. Avoid edges, folds, seams, or creases, since those can distort or hide the code.
• Use a clean surface. Wrinkles, tape over the barcode, smudges, or reflective surfaces can interfere with scanning.

If USPS can't read your barcode, the package may get treated as unpaid or flagged for manual review, which can delay delivery or lead to it being intercepted.

Does dropping off my package immediately after buying a label cause issues?

Yes, in some cases. After you purchase a USPS label, there's a short window while USPS systems confirm payment and process the Shipping Payment Electronic File (SPEF). If you hand off your package to USPS too soon after buying the label, their system may not have registered the payment yet, which can make it look unpaid or trigger extra review.

To help avoid this, wait 60 minutes between purchasing your label and dropping off the package. During peak shipping periods, that extra buffer reduces the chance of a payment-related flag.

Do you have cubic pricing?

Yes. USPS cubic pricing is available in Shippo. The discounted pricing we've negotiated with USPS is complex, using cubic pricing where it applies and weight/zone pricing elsewhere. We've optimized our pricing model to get you the best possible rate.

What are the character limits for USPS label fields?

USPS places these character limits on label address fields:

• Name: 38 characters
• Street 1: 36 characters
• Street 2: 36 characters
• Street 3: 36 characters (international shipments, API only)
• City: 15 characters
• State: 2 characters
• Customs declaration item descriptions: 30 characters

Note: USPS won't return an error if you exceed these limits. It just cuts off the field at the limit.

Can I create a return label with USPS Ground Advantage?

Yes. USPS Ground Advantage supports return labels, and those labels include up to $100 of carrier-included insurance.

USPS service levels

Why can't I see USPS First-Class Package and Parcel Select rates?

Effective July 9, 2023, USPS merged First-Class Package Service and Parcel Select Ground into a single, streamlined ground service level called USPS Ground Advantage, offering a simpler, more reliable, and more affordable way to ship packages up to 70 lbs in 2-5 business days.

What is USPS Ground Advantage?

USPS Ground Advantage is an affordable and reliable way for you to ship packages up to 70 lbs in 2-5 business days. You can ship domestically to all 50 states, U.S. military bases, territories, possessions, and Freely Associated States. Commercial rates for USPS Ground Advantage are lower than rates for First-Class Package Service and Parcel Select Ground by 0.7%.

What should I consider when choosing between USPS Ground Advantage and USPS Priority Mail?

• Price: Ground Advantage is cheaper than Priority Mail in every case.
• Speed: Priority Mail arrives faster.
• Packaging: USPS provides free packaging for Priority Mail.

Why can't I see USPS Priority Mail Express rates?

Priority Mail Express rates only show up if you enter your own dimensions, or if you choose Flat Rate Envelope, Flat Rate Padded Envelope, or Flat Rate Legal Envelope from the package type menu.

If you're not seeing Priority Mail Express rates, it's likely tied to your packaging selection. For example, USPS Flat Rate Cardboard Envelope only returns a Priority Mail rate. Selecting USPS Flat Rate Envelope (without "cardboard") shows both Priority Mail and Priority Mail Express rates.

I'm using a triangular-shaped box from USPS. Is this a tube? Which package option should I pick?

For odd-shaped packages, like circles, tubes, pyramids, or anything that doesn't fit the standard length x width x height format, choose USPS Irregular Parcel.

To do this, click the dropdown in the "Enter Your Package Information" section, select Carrier Provided Parcels, then choose USPS Irregular Parcel (4.0x4.0x4.0 in.). The LxWxH shown isn't a factor in your rate. Rate is calculated based only on the weight you enter, and the "4x4x4" is just a placeholder.

Alternatively, measure your box or tube following USPS Postal Explorer's recommendations and enter the LxWxH manually. Either way, your Priority Mail rate comes out the same.

Errors and delivery confirmation

Error calculating postage rates for one or more mail classes. Which selected services apply?

USPS doesn't support adding Signature Confirmation to international shipments. Try your purchase again without Signature Confirmation.

Is USPS Delivery Confirmation included?

For domestic shipments: Delivery confirmation is included on every domestic USPS rate you see in Shippo, built directly into the price.

For international shipments: Delivery Confirmation (EDELCON) is only available for a limited set of package types:

• First-Class Package International Service
• Priority Mail International Flat Rate Envelopes
• Small Flat Rate Boxes

It's also limited to a specific list of destination countries, available on the USPS website. If your package meets both the package type and country criteria, EDELCON gets applied automatically.

If EDELCON is applied, your label will say "EDELCON SERVICE" or show the "Post Expres" logo. If you don't see that and believe your package qualifies, let us know at support@shippo.com.