Custom GLS integration
Appfront builds custom GLS integrations that automate your shipping process, from your webshop, WMS, ERP or OMS. Through the GLS Web API we register consignments, generate shipping labels and retrieve track-and-trace data, so the shipment status flows back into your back end automatically. Your customers can see where their parcel is, and your team ships without manual work, even at high volumes.
What is a GLS integration?
GLS is a large international parcel carrier active in the Netherlands and across the rest of Europe. The carrier provides parcel delivery, supplies shipping labels and track-and-trace, and offers delivery options such as ParcelShops and pick-up points, plus returns. For organisations that ship their own parcels, GLS is therefore a logical shipping partner for domestic and European consignments.
In practice, a custom integration means: automatically registering consignments with GLS based on an order, generating shipping labels in PDF or ZPL for your printer, retrieving track-and-trace data and passing it on to your customer, showing delivery options and ParcelShops at checkout, creating return labels, and making the current shipment status visible in your webshop, WMS or ERP. For high volumes, we add batch label generation.
Appfront builds in line with the official GLS API developer documentation and the OWASP ASVS security standard. We align the label, tracking and returns flows with your actual shipping process, so the integration grows with your volume and your parcels leave reliably even during peak periods.
Bespoke shipping labels
Labels are generated automatically when an order comes in, in PDF or ZPL for your label printer. The unique consignment number is returned directly from the API and recorded against the order, so there is no more manual retyping.
Real-time track-and-trace
GLS status data is retrieved and passed back to your customer and your back end. From registered to delivered, everyone can see where the parcel is, without your customer service having to look up the shipment.
Delivery options & returns
ParcelShops and pick-up points are shown in the checkout, and you create return labels within the same flow. Your customer chooses a delivery option that suits them, and a return is arranged with a single click, visible straight away in your back end.
Our development process for GLS integrations
We work to a proven methodology that removes uncertainty early and delivers a stable integration. From an initial analysis of your shipping process, volumes and systems through to go-live and ongoing management, every step is aimed at an integration that your team can understand and trust.
We map out which shipments you send, from which system (webshop, WMS, ERP or OMS), what shipping volume you handle, and which delivery options, returns and batch shipping are relevant to you.
We design the integration architecture, select the right authentication using API credentials, and define an error-handling strategy.
Implementation with automated tests, structured logging and monitoring. You see working builds along the way.
Controlled go-live with data validation and a safety net, followed by ongoing management and further development.
What a GLS integration delivers in practice
Every GLS integration is tailored to your type of shipments, shipping volume and the systems around it. Below are the features we most often deliver for organisations that use GLS as part of their shipping process.
Generating shipping labels
For every order, a GLS label is generated automatically via the Web API, as a PDF or ZPL for your printer. The parcel number comes back from the API and is linked straight to the order in your webshop, WMS or ERP.
Returning track-and-trace
We retrieve status data from GLS and feed it back to your customer and your back end. From dispatch to delivery, everyone stays informed, with status updates arriving via the Tracking API and webhooks.
Delivery options & ParcelShops
In the checkout, we display GLS delivery options and nearby ParcelShops and pick-up points based on the address. Your customer chooses where the parcel is delivered, which improves the delivery experience and reduces failed deliveries.
Return labels
Return labels are created within the same flow via the API, so a customer can return an item with a single click. The return shipment appears in your back end, making it easy for your logistics team to schedule and process returned parcels.
Batch shipping at volume
If you send many parcels a day, we add batch label generation: in a single run, all shipments are registered and all labels are created. Your shipping process scales with peak periods without your team having to handle each order manually.
Shipping status in your back end
Every status change from GLS flows back into your own system, linked to the order. Your team sees in one overview which parcels are in transit, delivered or delayed, without switching between the GLS portal and your own software.
Typical use cases in practice
A GLS integration looks very different from one organisation to the next. We see a number of recurring patterns, and for each we have a proven setup covering labels, track-and-trace, delivery options and the right connection to your systems.
Online shops
Online retailers that ship their own orders via GLS. Shipping labels are created automatically when an order comes in, track-and-trace updates go back to the customer, and delivery options appear at checkout. See also our Shopify integration and broader API integrations.
Fulfilment partners
Logistics service providers that prepare and dispatch parcels for multiple clients. Batch label generation and integration with the WMS keep high volumes moving smoothly, with track-and-trace visible per client.
Retailers
Retail chains with an omnichannel approach that ship online orders from store or distribution centre. GLS labels and track-and-trace integrate with the OMS, so click-and-collect and home delivery run from a single system.
Wholesale
B2B wholesalers that supply business customers with larger, regular shipments. A GLS integration from the ERP keeps orders, labels and shipping status in sync, with batch dispatch for recurring deliveries.
Technology we use
We build GLS integrations using the official GLS Web API and its label, shipping and tracking endpoints, combined with the back-end stack that suits you. The precise choice depends on your webshop, WMS or ERP and your shipping volume, so that your own team can manage or further develop the integration.
Why choose Appfront for your GLS integration?
Appfront has extensive experience building API integrations for a wide range of organisations in the Netherlands. We always start with a thorough analysis of the existing systems and processes. An integration has to be technically sound, but it also has to add practical value to your shipping process.
For every integration, we write clear documentation and make sure your own team, or any future supplier, can understand and manage it. No black box, just transparent code and clear agreements on monitoring, alerting and maintenance.
You work with a dedicated point of contact who understands both the technical and the functional side. This keeps communication short, prevents misunderstandings and speeds up decisions when choices need to be made during development.
Also take a look at our other shipping integrations, such as DHL, DPD, PostNL and the shipping platform Sendcloud, plus our broader services in API integrations, middleware and custom software.
- Experience with the GLS Web API, label, shipping and tracking endpoints
- Specialists in integrations with webshops, WMS, ERP and OMS
- Familiar with delivery options, ParcelShops, return labels and batch shipping
- Secure by default: credentials in vaults, scoped permissions, encrypted traffic
- Structured error handling and retry mechanisms
- Comprehensive logging and monitoring from day one
- Clear documentation your team can read and manage
- A fixed point of contact, no account managers passed around
- Ongoing maintenance and proactive further development
- A way of working aligned with your existing IT landscape
Security and privacy in GLS integrations
A shipping integration always processes address and personal data of your customers. Name, delivery address and contact details are part of every shipment. Appfront builds in line with GLS security best practices and the OWASP ASVS. This includes storing API credentials in secure vaults, encrypting data in transit, scoping permissions tightly and carrying out regular audits of the label, tracking and return flows.
We only process the data needed to create and track a shipment, following the principle of data minimisation. We document the data flows and integrations so that your record of processing activities is complete and you can demonstrate compliance with the GDPR. Personal data is not kept longer than necessary for the shipping process.
More on our security approach: information security policy and CVD policy.
- GDPR-compliant data processing and data minimisation
- Encryption in transit (TLS 1.2+) and at rest
- Role-based access and least-privilege principles
- Audit logs with traceable data flows
- Automatic retries and dead-letter queues
- Monitoring and alerting for anomalies
- Secrets management in line with best practice
- Documentation for your record of processing activities
Frequently Asked Questions About GLS Integrations
Answers to the questions we are asked most often about GLS implementations.
A GLS integration is a technical link between GLS and another system, such as your webshop, WMS, ERP or OMS. Through the GLS Web API, shipments are registered programmatically, shipping labels are generated and track-and-trace data is retrieved. Status updates flow back into your backend, so your team and your customers can see where a parcel is. An integration can be simple (generating labels when an order comes in) or extensive (batch shipping at volume, delivery options with ParcelShops and return labels in a single flow).
GLS is strong for parcel delivery in the Netherlands and across Europe. A direct GLS integration makes sense if you handle a high shipping volume with GLS or have specific GLS requirements around labels, delivery options or returns. Many webshops also use a shipping platform such as Sendcloud that bundles multiple carriers; this is useful if you work with several carriers. We will look together with you at whether a direct integration or a platform approach best suits your situation.
A simple integration (registering shipments, creating shipping labels and retrieving track-and-trace) can go live relatively quickly. More extensive scenarios, such as batch label generation at high volumes, delivery options and ParcelShops, return labels and a deep integration with your WMS or ERP, usually take longer. After an intake meeting, we provide a realistic estimate based on your shipping volume and systems.
We work with the official GLS Web API (Shipping & Tracking) and the associated label, shipment and tracking endpoints, combined with the backend stack that suits you: Node.js, Python or PHP. Authentication runs through API credentials. We retrieve labels as PDF or ZPL for your printer. For the integration with your webshop, WMS or ERP, we use connectors and webhooks, so shipping statuses flow back into your backend automatically.
The cost is determined by the complexity of the data flows, the number of systems to connect, the shipping volume and the amount of custom work in the business logic, such as batch shipping, delivery options and return flows. Ongoing management, monitoring and support also affect the total investment. We always provide a clear quote after a no-obligation analysis of your situation.
Yes. A shipping integration processes your customers' address and personal data, so we handle it with care. Appfront builds to the OWASP ASVS: API credentials are kept in secure vaults, data traffic is encrypted, rights are scoped and access is strictly separated per integration. We only process the data needed for the shipment and document the data flows, so your record of processing activities stays complete and you can demonstrate compliance with the GDPR.
Yes. Appfront regularly takes over existing shipping integrations, even if they were originally set up by another party. We review the API integration, the label and tracking flows, the returns handling and the error handling, document the current setup and propose improvements. From that point on, we can manage adjustments, extensions and monitoring, including timely rotation of API credentials.
A GLS integration suits organisations that ship parcels themselves, such as webshops, fulfilment partners, retailers and wholesalers. Typical use cases: generating shipping labels automatically when an order comes in, passing track-and-trace updates back to the customer, showing delivery options and ParcelShops in the checkout, creating return labels and making shipping status visible in your back office. For high volumes we add batch label generation, so your shipping process scales without manual work.
Ready to build your GLS integration?
Tell us which system you ship from (webshop, WMS, ERP or OMS) and what volume you handle with GLS. We're happy to advise on labels, track and trace, delivery options, ParcelShops and returns. A no-obligation first conversation will give you a clear picture of what's possible within half an hour.