A shipment tracking API is the technical connection that pulls delivery status data from a carrier's systems into your application, dashboard, or customer notification workflow. Without a tracking API, getting status data means logging into each carrier's portal manually — which does not scale when you are managing shipments across UPS, FedEx, USPS, LTL carriers, and regional parcel services simultaneously.
Shipment tracking APIs eliminate that manual work. They return structured tracking event data — pickup confirmation, in-transit scans, out-for-delivery status, delivery confirmation — on demand or via webhook push, allowing any application consuming the API to display current shipment status without carrier portal access.
This guide explains how shipment tracking APIs work, what data they return, how to evaluate and implement them, and which platforms provide the best API coverage for logistics operations.
Key Takeaways
- A shipment tracking API returns carrier-generated tracking events as structured data (JSON or XML), enabling any application to display current shipment status without carrier portal access.
- Individual carrier APIs (UPS Developer, FedEx Web Services, USPS Web Tools) each require separate integration; multi-carrier aggregation APIs (AfterShip, EasyPost, ShipStation API, Shippo) unify tracking across dozens of carriers in one integration.
- Webhook-based tracking APIs push events to your system as they occur; polling APIs require your system to query on a schedule — webhooks are preferable for real-time customer notification use cases.
- Tracking API coverage varies significantly by carrier and region: domestic US parcel coverage is nearly universal across major aggregators; international, LTL, and regional carrier coverage varies and should be verified before integration.
- Custom tracking portal builds using multi-carrier APIs typically cost $40,000 to $80,000 and replace fragmented carrier portal log-ins with a branded customer experience pulling from all carriers in use.
How Shipment Tracking APIs Work
The Data Flow
A shipment tracking event starts when a carrier scans a package at a physical touchpoint: pickup from sender, arrival at origin sort facility, departure for destination, arrival at delivery hub, out for delivery, delivered.
Each scan creates a tracking event in the carrier's system: a timestamp, a status code, a location, and sometimes descriptive text. The carrier exposes those events through an API endpoint.
When your system calls the tracking API with a tracking number, the carrier's API returns the history of all events recorded for that shipment. The response is structured data — typically JSON — that your application parses and displays.
Event Types
Standard tracking events across most carrier APIs:
- Label created: Shipment label printed by sender; carrier has not yet received the package
- Picked up: Carrier scan confirms pickup from sender
- In transit: Package moving through the carrier network; may include sort facility scans
- Out for delivery: Package loaded on delivery vehicle for final delivery attempt
- Delivered: Delivery confirmation scan; may include recipient name or GPS coordinates
- Delivery attempted: First delivery attempt; recipient not available
- Exception: Shipment delayed, held, or requiring customer action
Polling vs. Webhooks
Polling: Your system calls the carrier API on a schedule (every 15 minutes, every hour) to check for new events. Simple to implement but introduces latency; a delivery event at 10:05 AM may not appear in your system until 11:00 AM if you poll hourly.
Webhooks: The carrier API pushes a notification to your endpoint when a new event occurs. Your system receives the event in near real time without polling overhead. Preferable for customer notification use cases where delivery event latency matters.
Not all carrier APIs support webhooks. USPS and many LTL carriers provide polling-only APIs; major parcel carriers (FedEx, UPS) support webhooks on enterprise API plans.
Individual Carrier Tracking APIs
UPS Developer Portal
UPS provides a REST API for shipment tracking. Authentication requires UPS API key registration. The Tracking API returns event history, current status, and scheduled delivery date for UPS shipments.
UPS API notable features:
- Real-time tracking event delivery via webhook (on Quantum View Manage plan)
- Returns estimated delivery date alongside event history
- Covers UPS domestic, UPS Mail Innovations, and UPS SurePost
- Rate limits apply by API tier; high-volume integration requires negotiated API access
FedEx Web Services / FedEx Developer Portal
FedEx provides REST and SOAP tracking APIs. The REST API is the current recommended integration. Returns tracking events, estimated delivery, and signature proof-of-delivery information.
FedEx API notable features:
- Event-based notifications available through FedEx Insight subscription
- Supports FedEx Express, FedEx Ground, and FedEx SmartPost
- Returns estimated delivery date with delivery time window
- Multi-piece shipment tracking (master tracking number returns all piece events)
USPS Web Tools
USPS provides a tracking API through the USPS Web Tools program. Authentication is via USPS Web Tools user ID. The API is SOAP/XML, older in design than modern REST APIs, and requires a registered USPS Web Tools account.
USPS tracking API limitations:
- SOAP/XML format is more complex to parse than modern JSON APIs
- No webhook support; polling required
- Rate limiting enforced; high-volume integration requires enterprise USPS API access
- Coverage is limited to USPS-handled packages; packages handed off to local post offices may have gaps
LTL Carrier APIs
LTL carrier tracking API availability and quality varies significantly. Large carriers (XPO Logistics, Old Dominion, Estes, SAIA) provide tracking APIs; smaller regional LTL carriers may offer only portal-based tracking or EDI-based status updates.
LTL tracking events are less granular than parcel tracking: most LTL carriers report pickup, in-transit (with fewer intermediate scans than parcel), and delivery rather than the frequent scan chain that parcel tracking provides.
Multi-Carrier Tracking API Aggregators
For operations shipping with multiple carriers, individual carrier API integration is impractical — each carrier requires separate authentication, different data formats, and separate maintenance when carriers update their APIs.
Multi-carrier API aggregators provide a single API that normalizes tracking data across dozens of carriers into a consistent format.
AfterShip
AfterShip is the most widely used multi-carrier tracking aggregator for e-commerce. It covers 1,100+ carriers globally, returns normalized tracking data in a consistent JSON format, and supports webhooks for real-time event push.
AfterShip capabilities:
- Carrier detection from tracking number format (identifies carrier from tracking number without user input)
- Webhook-based event push for all connected carriers
- Branded tracking page builder (no-code customer tracking experience)
- Returns standardized status codes across all carriers (instead of carrier-specific codes)
- Pricing: starts at $9/month for 100 shipments; enterprise pricing for high-volume operations
EasyPost
EasyPost is a multi-carrier shipping API that includes tracking across supported carriers. Unlike AfterShip (tracking-only), EasyPost covers rate shopping, label generation, and tracking in one integration.
EasyPost tracking capabilities:
- Tracking webhooks for event push across covered carriers
- Standardized event types across carriers
- Covers major US domestic carriers and international carriers
- Pricing: per-shipment or per-tracking-number; pricing scales with volume
Shippo
Shippo provides multi-carrier label creation and tracking APIs for e-commerce and small logistics operations. Strong parcel carrier coverage; weaker on LTL and freight.
project44 and FourKites
For enterprise shippers and 3PLs, project44 and FourKites provide multi-modal visibility APIs covering parcel, LTL, truckload, ocean, and air freight. These platforms go beyond tracking event aggregation to provide predictive ETA, exception management, and supply chain visibility analytics.
Enterprise multi-modal tracking APIs are more expensive and require integration work, but provide visibility depth that parcel aggregators do not match for logistics-scale operations.
Building with a Shipment Tracking API
Use Cases for Tracking API Integration
Customer-facing tracking portals: Display current shipment status on your website or branded portal, pulling from all carriers in use. Eliminates "where is my order?" inquiries to customer service.
Automated delivery notifications: Trigger email or SMS notifications when tracking events occur (shipment picked up, out for delivery, delivered). Reduces customer uncertainty and inbound service contacts.
Operations dashboards: Surface in-transit shipments with exception status for your logistics operations team. Flag delayed shipments before customer complaints.
Analytics and reporting: Capture delivery event timestamps for on-time delivery reporting, carrier performance scorecarding, and transit time analysis.
Returns tracking: Track inbound return shipments using the same API integration as outbound tracking.
Integration Steps
- Select carrier API or aggregator: Determine whether individual carrier APIs or a multi-carrier aggregator fits the carrier mix and volume requirements.
- Register and authenticate: API key registration is required for all major carrier and aggregator APIs. Enterprise plans may require account negotiation.
- Implement tracking number ingestion: When a label is created in your OMS or TMS, pass the tracking number to the tracking API and store the carrier reference.
- Set up webhook endpoint (if webhook-based): Configure your application endpoint to receive event push notifications and handle carrier-specific event processing.
- Normalize event data: Map carrier-specific status codes to your application's status model. AfterShip and EasyPost normalize this; individual carrier APIs require custom mapping.
- Build the presentation layer: Display normalized tracking data in your customer portal, operations dashboard, or notification workflow.
Custom Shipment Tracking Portal Development
For operations that need branded tracking experiences beyond what off-the-shelf tracking portals provide, custom portal development uses the multi-carrier tracking API as the data source and builds the customer-facing and operations-facing application on top.
Custom tracking portals built over multi-carrier APIs deliver:
- Branded customer experience matching the company's design system
- Multi-carrier tracking in a single view without exposing carrier details to customers
- Operations dashboard with exception management and SLA alerting
- Analytics reporting on transit time performance and carrier on-time rates
LOW/CODE Agency builds custom shipment tracking portals over multi-carrier APIs for logistics companies and e-commerce brands, delivering carrier-agnostic tracking experiences with operations dashboards and delivery analytics. With 350+ production applications and enterprise logistics clients, our practice delivers tracking portal builds at $40,000 to $80,000. Schedule a consultation with our Senior Partners to discuss your shipment tracking portal requirements.
Frequently Asked Questions
What is a shipment tracking API?
A shipment tracking API is a software interface that returns carrier-generated tracking events as structured data, allowing any connected application to display current shipment status without requiring access to the carrier's tracking portal.
What is the difference between polling and webhook tracking APIs?
Polling requires your system to query the carrier API on a schedule to check for new events. Webhooks push new events to your system as they occur. Webhooks are preferable for real-time customer notification; polling is sufficient for batch reporting use cases.
Do all carriers have tracking APIs?
Major carriers (UPS, FedEx, USPS) have tracking APIs. LTL carrier API availability varies by carrier. Regional and international carriers have inconsistent API coverage. Multi-carrier aggregators like AfterShip extend coverage to 1,000+ carriers, though smaller carriers may have delayed data or limited event granularity.
What is AfterShip used for?
AfterShip is a multi-carrier tracking aggregation platform that provides a single API connecting to 1,100+ carriers worldwide. It is used to power customer-facing tracking pages, delivery notifications, and operations dashboards without building individual carrier integrations.
How much does shipment tracking API integration cost?
Basic integration with a multi-carrier aggregator (AfterShip, EasyPost) requires 40 to 80 hours of development time for standard implementations. Custom tracking portal development with branded UI and operations dashboards typically costs $40,000 to $80,000.