Due to changes to USPS’s Business Account platform, all customers using Auctane-hosted products (such as Stamps.com, Endicia, ShipStation, or ShipStation API) must grant Auctane permission to maintain their specific Negotiated Service Agreement (NSA) rates.
For an overview of how Negotiated Service Agreement (NSA) customers use a USPS Enterprise Payment Account (EPA) with a ShipStation API account, see our USPS Business Portal & Enterprise Payment Account (EPA) page.
New to the USPS Business Portal and NSA Rates? Please see our page for New Customers: Link Your USPS Business Account to Stamps .
Action Required: Link Accounts to Keep USPS NSA Rates
You must link your account to continue using your USPS NSA Rates. Customers who do not complete this new linking process will lose access to their NSA rates when printing USPS labels.
Required:
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For contract rate mapping
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To call tracking data on your behalf
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As a contractual precursor to our API migration
To complete the COP process, you’ll need the following information (or request them from your USPS sales representative):
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CRID (Customer Registration ID): Required for final setup.
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MID (Mailer ID): Required for final setup.
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EPS (Enterprise Payment System) Number: Required for final setup.
Warning: Reset Password as Last Resort
Resetting your password will immediately break all active connections, including partner platforms, 3PL systems, and custom integrations. Only reset if absolutely necessary, as you must manually update your credentials across every connected system to avoid label printing errors.
Please note that for security reasons, Support cannot retrieve or provide existing passwords.
If you have connected your NSA rates to your existing ShipStation API account, follow these steps on Stamps.com.
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Log in to your Stamps.com account.
Having trouble finding your Stamps login?
If you're not a direct Stamps customer, please note that you’re being directed to log in to Stamps because it serves as the underlying postage engine for your account.
To log in to Stamps:
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For all platforms: First try logging in with your account credentials associated with the platform you work out of (e.g. ShipStation, ShippingEasy, ShipWorks, etc.). Having trouble finding your Stamps login?
If this doesn't work, please contact Stamps Support.
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ShipWorks customers can identify their Stamps credentials by using the Stamps.com: What Is My New Account Username and Password? article.
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ShipStation customers can identify their Stamps credentials this way:
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Go to Settings, select Shipping > Carriers.
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Locate the Stamps or USPS (ShipStation) tile. The Username or Account Number is typically displayed on this screen.
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Choose one of two ways to connect.
When you first log in, you will be prompted to connect your account through one of two ways:
Connection Pop-up: Click See Guidelines to begin from the pop-up titled Connect Your USPS Business Account that will appear.
or
Dashboard Banner: Click See Guidelines within the persistent banner that reads, Connect your USPS Business Account to Stamps.com to access NSA rates. This banner will remain at the top of your dashboard.
After you click See Guidelines, you’ll be taken to the Connect USPS Business Account Settings page within Stamps.com.
The connection process requires a critical authentication step that grants your ShipStation API account access to charge you the correct, discounted NSA rates on your labels.
Already have a USPS Business Account AND a linked EPA?
If you already have a USPS Business Account AND a linked EPA, you may skip to Step 4. However, if you have an account but no EPA, you must follow these steps to add one.
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Click the link labeled Setup Your USPS Business Account In the New to USPS? section of the guidelines.
A new browser tab will open to the USPS login page.
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If you need an account: Click Create New Account, validate your email, and complete the three-step setup wizard.
If you have an account: Sign in with your existing USPS.com credentials.
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Locate the section Add Your Payment Account to Get Started once you land on your Business Portal dashboard.
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Check the box that reads, "I have read, understand, and agree to the Payment Account Terms and Conditions", then select your payment method (ACH Debit), click Continue, and complete the required setup steps.
Mandatory Connection Requirement
While the UI may suggest this step is optional, it is mandatory to complete the connection to Stamps.com. Do not skip this step!
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Return to the original Stamps.com browser tab to continue, once your payment method is successfully added (it may show as Pending for ACH).
With your USPS Business Account and EPA established, you can now link them to Stamps.com.
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Click Link your business account in the Finalize Your Connection section of the guidelines.
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Sign in to your USPS.com account and complete the Multi-Factor Authentication (MFA) flow as prompted.
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Check the agreement box and click Authorize and Continue on the Grant Auctane Access screen.
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Click the large Go to Auctane button to finalize the link on the Successful Integration screen.
You will be redirected back to the Stamps.com interface to complete the final step: Input your CRID, MID, and EPS IDs.
