June 24, 2026 · Integration · 5 min read

DHL Integration in Depth: All Features at a Glance

DHL is the most important carrier for most German online retailers – yet much of the DHL API's potential remains untapped because retailers only use it through the business customer portal rather than an integrated solution. Colly.io uses the DHL API fully. Here's what that means in practice.

Standard Shipping: Labels with One Click

The most common use case: order arrives, print label, ship package. In Colly.io, the appropriate DHL product is automatically suggested for each order – small parcel S/M, parcel, oversized – based on item weight and dimensions. Labels are sent as ZPL or PDF directly to the connected printer.

Simultaneously, the tracking number is automatically transmitted to the marketplace or shop from which the order originated. No manual copying, no logging into separate portals.

Express and Time-Window Delivery

For orders with SLA requirements, Colly.io supports DHL Express and DHL Paket Express with guaranteed transit times. Carrier selection can automatically switch to Express when an order is marked urgent or when a specific channel requires Express by default.

Return Labels and DHL Retoure

Return labels can be generated directly in Colly.io and delivered to customers by email. In RMA processes, the return label is automatically generated in the "Label created" process step.

Preferred Delivery Services

When printing labels, Colly.io automatically transmits all available DHL preferred delivery services the customer has specified: preferred neighbor, preferred location, and preferred time. This information comes directly from the order and is passed to DHL without manual intervention.

Tracking Webhooks and Event Updates

DHL sends tracking events via webhook: "Out for delivery," "Delivered," "Undeliverable." Colly.io processes these events automatically and updates the order status accordingly. For delivery problems, an automatic notification to the retailer can be configured.