How to Choose the Right Shipping Software for Your USPS NSA

If you're shipping 2,500+ packages per month, a USPS Negotiated Service Agreement (NSA) can dramatically lower your postage costs. But the real unlock doesn’t come from the contract alone, it comes from the shipping software you choose to connect that NSA into your day-to-day operations.

Pick the right platform and you’ll:

• Actually see your negotiated rates at work
• Keep your USPS relationship in good standing
• Automate the busywork that eats your team’s time
• Compare USPS against other carriers to protect your margins

Pick the wrong one, and you can end up with misapplied rates, compliance issues, manual workarounds, and frustrated customers.

This guide walks through seven critical areas you should evaluate when choosing a shipping solution to integrate with your USPS NSA — with examples of how Easyship helps you get it right.

7 Factors To Take Into Consideration

There are a lot of shipping tools on the market, but for a high-volume merchant with a USPS NSA, the decision comes down to a focused set of questions:

1. NSA Compatibility – Does the platform properly support USPS Hosted NSA connections and contract rates?
2. USPS Certification – Has the software gone through USPS-approved certification programs?
3. Ability to Maintain USPS NSA Commitments – Can it help you stay on top of volume, scan, and performance obligations?
4. Comparing NSA Rates With Different Carriers – Does it make it easy to see when USPS is best vs UPS, FedEx, DHL, etc.?
5. Integration With eCommerce Software – Will it plug into your storefronts without custom development?
6. Tracking: Volume Tracking, Shipment Tracking & Notifications – Does it give you the visibility USPS expects and your customers demand?
7. Automation, APIs & Enterprise Integrations – Can it scale with ERPs, WMS, and advanced workflows?

These aren’t isolated boxes to tick. They work together: solid NSA compatibility is useless without tracking; automation is limited without good eCommerce integrations; and none of it matters if you can’t compare actual landed costs across all your carriers.

Does the Platform have NSA Compatibility?

The very first check is simple: does the platform natively support USPS Hosted NSAs?

You want a solution that:

• Lets you securely connect your USPS NSA credentials (CRID, MID, EPS, etc.) directly in the dashboard
• Applies your contract rates automatically during rate shopping and label generation
• Respects USPS rules around label formats, tracking, and data exchange
• Doesn’t require custom, one-off development just to go live

If you’re stuck building custom middleware, emailing spreadsheets, or manually applying rate tables, you’re not really leveraging your NSA — you’re just adding more work.

How Easyship fits in:
With USPS Hosted NSA on Easyship, you simply:

1. Go to Your Own Courier Accounts in the dashboard
2. Add a new courier → select USPS
3. Enter your USPS details (CRID, Master MID, Child MID, EPS)
4. Log in via USPS COP to authorize

From there, your USPS NSA rates are live inside Easyship for both checkout and label creation, with no custom integration required.

Does the Software have USPS Certification?

When you’re tying a negotiated USPS contract into a third-party platform, you want to know that the software is actually certified by USPS’s own certification or partner processes — not just “it seems to work.”

USPS maintains formal certification and partner programs and publishes lists of certified software vendors and providers on its PostalPro site. Many multi-carrier platforms and shipping tools also highlight their status as USPS partners or preferred solutions publicly.

In practice, that means looking for software that:

• Is recognized by USPS in official documentation or partner programs
• Follows USPS standards for labels, tracking data, and acceptance
• Has experience with USPS Ship / USPS APIs, not just basic Web Tools

You don’t need to memorize the entire PostalPro spreadsheet of certified vendors, but you should confirm that your shipping software has passed through USPS approval in some form and isn’t just “hacking” labels together.

Examples of USPS-integrated or partner solutions commonly seen in the market include multi-carrier platforms and postage tools such as Easyship and several other USPS-partnered shipping software vendors. Many of these appear in USPS resources or describe themselves as official USPS partners or Business Alliance partners in their own materials.

For you as a merchant, USPS certification or partnership is less about logos on a slide and more about confidence that:

• Labels will scan without issue
• Tracking events will flow correctly
• USPS will honor the way your contracts are being used

Maintain the USPS NSA Volume Commitments

A USPS NSA isn’t just “better pricing.” It comes with commitments—usually around:

• Monthly or yearly volume
• Use of specific mail classes or products
• Scan performance and data quality
• Operational practices (e.g., manifesting, acceptance, etc.)

If you don’t keep up with these commitments, USPS can adjust pricing, revoke benefits, or decline to renew your NSA.

For example: if your NSA requires 20,000 Priority Mail packages per quarter and your shipping software can’t accurately track service mix by product, you might think you’re on target while actually falling short—putting you at risk of losing your discounted rates or even your NSA entirely.

This is where your shipping software quietly becomes a risk mitigation tool. A good platform will help you:

• Monitor your NSA volumes against targets
• Track scan events and on-time performance
• Export or share reports that align with USPS expectations
• Keep all USPS data structured and consistent

Rather than trying to track this in spreadsheets or ad hoc dashboards, it’s far easier to lean on a platform designed to handle high-volume USPS shipments with NSA-level reporting.

Because Easyship centralizes all your USPS traffic along with other carriers, it’s simple to see:

• How many USPS packages you’re shipping over a period
• Service mix (Priority Mail, Ground Advantage, etc.)
• Where performance issues might put you at risk

That visibility makes it much easier to stay within the spirit and letter of your NSA agreement.

Comparing NSA Rates With Different Carriers

An NSA gives you great USPS pricing, but it doesn’t guarantee that USPS is the best choice for every single shipment.

You still need to be able to quickly compare:

• USPS NSA rates vs. UPS, FedEx, DHL Express
• USPS vs. regional carriers in specific zones
• Different service levels for speed vs. cost trade-offs

If your shipping solution doesn’t make multi-carrier comparisons easy, you either:

• Default to USPS for everything (and quietly overpay on some lanes), or
• Spend hours manually checking rates across multiple systems

Neither approach is sustainable at 2,500+ shipments per month.

With Easyship, your USPS NSA rates show up right alongside 550+ other courier services in one dashboard. That makes it straightforward to:

• Use USPS where your NSA shines
• Switch to another carrier when they beat USPS on cost or SLA
• Expose “cheapest / fastest / best value” options to your customers at checkout

You keep your NSA advantage and protect your margins across the board.

Integration With eCommerce Software

If you’re selling on Shopify, WooCommerce, Squarespace, Wix, Etsy, eBay, Amazon, TikTok Shop, or any combination of those, your USPS NSA integration needs to fit naturally into your existing stack.

You shouldn’t have to:

• Manually export orders from your store
• Upload CSVs into your shipping tool
• Re-enter customer addresses
• Copy/paste tracking numbers back into each platform

That kind of setup guarantees:

• More errors
• Slower fulfillment
• Frustrated customers asking, “Where’s my order?”

Instead, look for a solution that:

• Offers native apps or plug-and-play integrations for your platforms
• Syncs orders automatically
• Pushes back tracking numbers and status updates
• Applies your USPS NSA rates directly at checkout if needed

Easyship integrates with 60+ eCommerce platforms and marketplaces, including Shopify and other major carts. Your orders sync automatically, your USPS NSA rates can appear at checkout as live options, and your team can manage all shipments from a single interface instead of jumping between tools.

Tracking: Volume Tracking, Shipment Tracking & Notifications

USPS cares about data. Your customers care about visibility. Your finance team cares about volumes and costs. Tracking sits at the center of all three.

When you’re operating under an NSA, you’ll want a platform that makes it simple to:

• See how much volume you’re running through USPS over time
• Confirm that packages are getting proper acceptance scans
• Monitor delayed or at-risk shipments
• Send proactive notifications to customers

Poor tracking doesn’t just create support tickets — it can also lead to:

• Missed volume targets
• Incomplete or inaccurate reporting
• Disputes over performance or adjustments

How Easyship supports this:

• Volume dashboards: Easily see USPS shipment counts over defined periods
• Shipment tracking: Central view of USPS and other carriers in one place
• Customer notifications: Automated emails (and optionally SMS) with tracking updates
• Exception visibility: Identify delays or missed scans before they snowball

That combination makes it easier to keep USPS happy, your customers informed, and your internal teams aligned without building custom reporting.

Automation & APIs

At NSA-level volumes, manual shipping processes don’t scale. The difference between a modern shipping platform and a basic label tool is often automation.

Areas where automation really pays off:

• Label creation: Batch printing and one-click label generation
• Rules and routing logic: “If weight < 1 lb and zone ≤ 4, use USPS X service,” etc.
• Address validation: Preventing bad addresses before they become failed deliveries
• Documentation: Auto-filled customs details for international, where relevant
• Service selection: Automatically choosing cheapest / fastest / best value

On top of that, enterprise and fast-growing brands often need APIs so they can:

• Plug shipping logic into internal systems
• Build custom workflows and dashboards
• Integrate with in-house tools or 3PL platforms

Easyship’s automation & API layer gives you:

• A flexible rules engine for carrier and service selection
• Automated address validation using USPS-compatible standards
• High-speed bulk label creation for batch fulfillment
• A REST API that your developers or partners can use to embed shipping directly into your order management systems

The result is a shipping operation that keeps up with your growth instead of holding it back.

How Do I Integrate USPS NSA With ERP and WMS Systems?

The next step when you’re at a stage of large volume shipping is to ensure that your USPS NSA can integrate with ERP and WMS systems. Once you’re operating at true enterprise scale, your USPS NSA has to live inside a broader ecosystem:

• ERP (e.g., NetSuite, Microsoft Dynamics, Acumatica)
• WMS (Warehouse Management Systems)
• OMS (Order Management Systems)
• 3PL or in-house fulfillment centers

If your shipping software is “off to the side,” it forces your team to swivel-chair between multiple platforms, creates data mismatches, and slows down fulfillment.

Instead, you’ll want a solution that:

• Integrates (or can be integrated) directly with your ERP and WMS
• Shares shipment data, costs, and tracking events back into your core systems
• Supports multi-warehouse, multi-account setups
• Handles multiple USPS NSA accounts if you operate across entities or divisions

Bringing It All Together

Evaluating shipping software for your USPS NSA isn’t just a technical exercise — it’s a strategic decision that touches your:

• Margins (through accurate contract rates and multi-carrier comparisons)
• USPS relationship (through compliance and performance)
• Operations (through automation, integrations, and tracking)
• Customer experience (through faster, more transparent delivery)

When you get all seven factors right — NSA compatibility, USPS certification, NSA commitments, rate comparison, eCommerce integration, tracking, and automation/enterprise tooling — your USPS NSA becomes a competitive advantage, not just a line item in a contract.

Easyship’s USPS Hosted NSA integration is designed specifically for high-volume merchants who want to connect their existing USPS contract and manage all of their shipping — USPS plus 550+ other services — in one powerful dashboard.

Ready to plug your USPS NSA into a modern multi-carrier shipping platform?

Sign up with Easyship and connect your account today!

Frequently Asked Questions

How do I know if my USPS NSA is compatible with a shipping software?

Your software should explicitly support USPS Hosted NSA connections and allow you to authenticate your USPS credentials (CRID, MID, EPS) directly inside the dashboard. If the platform doesn’t mention Hosted NSA support, your rates may not be applied correctly.

Do I need USPS-certified software to use my NSA?

While not every tool is USPS-certified at the same level, choosing a certified or USPS-partnered platform ensures your labels, tracking, and data exchanges follow USPS requirements. This reduces the risk of rejected shipments or NSA compliance issues.

What happens if I don’t meet my USPS NSA volume commitments?

Falling short of volume requirements or scan performance standards may impact your negotiated pricing or NSA eligibility. Using shipping software that tracks volume and scan data helps you stay on target and avoid penalties.

Can I still compare USPS NSA rates with UPS or FedEx?

Yes — and you should. Even with discounted USPS rates, other carriers may be cheaper or faster depending on weight, zone, or delivery speed. Multi-carrier rate comparison prevents overspending on certain lanes.

Do my USPS NSA rates automatically show at store checkout?

Only if your shipping software supports real-time checkout rates and applies your contract pricing during calculation. Easyship automatically uses your USPS NSA rates for Rates at Checkout once your account is connected.

Can multiple stores or warehouses use the same USPS NSA?

Most software tools, including Easyship, allow multi-store and multi-warehouse setups. Just ensure that your operational structure still meets USPS reporting and volume expectations under the NSA.

Does my team need technical expertise to connect a USPS NSA?

Generally no. Modern shipping platforms offer simple, guided setups that take only a few minutes. With Easyship, merchants connect their USPS NSA via a secure USPS COP login with no custom development required.

Can I connect multiple USPS NSA accounts to the same platform?

Yes. Many high-volume sellers manage multiple entities or divisions, each with its own USPS NSA. Easyship lets merchants add multiple USPS accounts under “Your Own Courier Accounts.”

Will connecting my USPS NSA affect my existing Easyship discounts?

Your own USPS NSA rates will override USPS options provided by Easyship, but you can still access discounted rates from other carriers on the platform. This gives you more flexibility, not less.

What should I do if I’m not sure whether I qualify for an NSA?

USPS typically offers NSAs to merchants shipping 2,500–3,000+ packages per month. If you're not sure, reach out to your USPS rep or Easyship’s shipping experts, who can guide you through eligibility requirements.

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