Carrier API Changes are Coming in 2026

Here’s Why That’s Actually Good News for Merchants

In 2026, major carriers including UPS, USPS, and FedEx will complete a shift that’s been years in the making: retiring legacy carrier APIs in favor of more modern, secure platforms. 

To some, this might seem like a time-suck that merchants and developers simply have to deal with. But there’s actually good reason for these changes. And with the right shipping infrastructure in place, they won’t create extra work.

In this article, we’ll dig into the real reasons carriers are overhauling their APIs, how they benefit eCommerce merchants, and how you can stay current without adding more work to your plate.

Table of Contents

• Carrier API Changes: Where Things Stand Today & What’s Ahead in 2026
• The Real Reasons Carriers are Overhauling Their APIs 
• What API Changes Mean for Merchants & Their Customers
• Looking Ahead: Future Proofing Your Store as Carrier Technology Evolves

Carrier API Changes: Where Things Stand Today & What’s Ahead in 2026

Carriers have been migrating their API infrastructure for several years. UPS was the first to phase out its legacy APIs in 2025. In 2026, USPS and FedEx are following suit.

UPS 

• Mid 2023: UPS rolled out a major update to its API infrastructure, transitioning from old access keys to a more secure OAuth 2.0 model. 
• Summer 2025: UPS sunset its legacy access key authorization for all APIs.  

USPS

• 2024: USPS began gradually transitioning out older APIs and replacing them with OAuth-secured, RESTful APIs. These are designed to improve reliability, reduce fraud, and deliver more precise shipping and delivery information.
• January 2025: USPS Web Tools API Versions 1 & 2 were retired.
• January 2026: USPS is switching off the last of its Web Tools APIs (Version 3). All merchants and solution providers should migrate integrations to the new USPS APIs by this date. 

FedEx

• 2022 – 2025: FedEx has been moving away from older SOAP-based APIs toward modern RESTful APIs, introducing new services, enhancements, and rate logic. Legacy FedEx Web Services WSDLs were disabled, replaced by FedEx REST APIs.  
• June 2026: Remaining SOAP-based endpoints will be fully retired. After this, integrations must use FedEx’s REST APIs to access rates, labels, tracking, and future service updates.

The Real Reasons Carriers are Overhauling APIs

There are three core drivers behind the push to modernize carrier integrations. 

1. Combat fraud and improve security 

In the past, carriers have faced issues with fraud and data security. Attackers actively targeted carrier APIs to scrape tracking data for phishing, intercept and reroute high-value shipments, or generate fake shipping labels. 

Carriers are responding by tightening how shipping data and accounts are accessed. Modern authentication standards give them more control over access, limit how long credentials can be used, and make abnormal behavior easier to detect. Stronger authentication and tighter access controls significantly reduce the risk of API abuse. 

2. Better serve merchants and consumers with fast, precise shipping data 

Shipping expectations have changed, and legacy API systems struggled to keep up.

Merchants and consumers want accurate delivery estimates, real-time tracking, and instant rate quotes. And they need coverage for every type of shipping scenario, from a simple single-item ground delivery to a multi-package international shipment. 

Older APIs relied on static service standards, approximate pricing logic, and multiple calls to handle a single shipment. Upgraded APIs return more precise delivery dates, handle pricing logic more accurately, and surface address issues earlier. In short, they offer far better support for the way eCommerce shipping actually works today. 

3. Support more dynamic carrier pricing

Traditionally, carrier pricing has followed predictable schedules: published base rates, annual increases, fuel surcharges, and seasonal peak fees layered onto negotiated contracts. While this still exists, modern APIs now allow pricing and service options to adapt in real time based on demand and capacity. 

As this shift continues, merchants can present the lowest-cost real-time shipping rates. Using platforms like ShipperHQ, they can connect to live carrier APIs and automatically compare carriers and transit times at the moment an order is placed. 

This shift is turning shipping from a fixed cost into something more flexible and responsive – similar to how travel sites compare airlines in real time to surface the best fare.

What API Changes Mean for Merchants and Their Customers

The modernization of carrier APIs helps merchants deliver on the Amazon-era expectations for shipping, while also preventing margin loss.  Shipping data is more precise and accurate upfront at checkout. Rates align more closely with carrier invoices. Delivery dates are easier to stand behind. Address issues are flagged earlier in the process. 

With modern carrier APIs, merchants can:

• Strengthen security and prevent fraud. Stronger security protocols make it harder to misuse shipping credentials, scrape tracking data, intercept packages, or generate fraudulent labels—reducing chargebacks, fraud losses, and support escalations.
• Improve reliability and performance at checkout. Modern carrier platforms are more stable and responsive, so shipping rates and delivery estimates load fast —helping reduce cart abandonment caused by slow or failed shipping quotes.
• Respond instantly to dynamic pricing. As carriers introduce more dynamic rates based on demand and capacity, merchants can choose the right carrier for each shipment as conditions change, using platforms like ShipperHQ for rate shopping. 
• Show delivery dates that reflect real-time conditions. Merchants will be able to offer delivery dates based on current transit conditions and capacity, as delivery APIs become more dynamic.
• Catch address issues before orders ship. Improved address validation that flags problems at checkout means fewer failed deliveries, fewer address correction fees, and fewer post-purchase support tickets.

Shoppers get more accurate and transparent delivery information upfront. Merchants get better margins, more conversions, and fewer support tickets.

Looking Ahead: Future-Proofing Online Stores as Carrier Technology Evolves

Nothing stands still in eCommerce. The UPS, USPS, and FedEx transitions highlight the new reality: carrier APIs don’t stand still. Even after these migrations are complete, carriers will continue updating pricing logic, delivery data, security requirements, and services.

If you manage a custom-built site or a site built on a highly customizable platform like Magento, you may face ongoing development work, testing, and redeployments as carriers make changes to their API integrations. To avoid costly, ongoing developer work, come talk to us at ShipperHQ. We support 75+ carrier integrations and manage all the technical updates for you. As new services and pricing structures roll out across carriers, ShipperHQ is right there with merchants, helping you take advantage of them without technical overhead.

Have Questions About Carrier API Changes?

If you’re wondering how these updates affect your store, or whether your current setup is ready for the upcoming legacy API switch-offs, ShipperHQ can help. We handle the complexity of carrier changes behind the scenes so merchants can focus on business growth. 

Learn more at shipperhq.com or contact our team. We look forward to helping merchants seamlessly integrate new carrier APIs and capitalize on all the benefits they offer.