Shipping Label Software: Create, Print and Automate Labels
A shipping label may look like a simple sticker, but it's the link between your checkout and your warehouse. Many retailers only decide which carrier to use once they're in the warehouse, per order or by habit. That works, but it means warehouse staff have to choose from an average of over 75,000 possible services and rates, depending on carrier, destination, weight, dimensions and service type. That's not a choice you want to make manually at 100+ orders per day.
When you let customers choose at checkout (carrier, delivery day, pickup point or home delivery), you shift that decision forward. The label is locked in before the warehouse even starts. That makes the packing process faster, more predictable and easier to plan. With GreenChoice, 88% of consumers choose deferred delivery, giving your warehouse more time to spread weekend orders across the week instead of cramming everything into Monday.
By connecting the label process to the checkout, you save on multiple fronts: labels are ready before the parcel is packed, your warehouse staff no longer needs to make choices, and you prevent errors that show up on the invoice later. Retailers who set this up properly save directly on staffing costs and processing time. Only very small webshops still book shipping labels one by one via the carrier's portal.
On this page, we explain how shipping labels work, what's on them, and how to automate label creation across multiple carriers.
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The Monday problem: why printing labels is more complex than it looks
Most B2C webshops receive the bulk of their orders over the weekend. On Monday, the warehouse has to process all those orders: collect items, pack them, generate labels and stage everything per pickup time and carrier. The result is a massive peak at the start of the week, followed by relatively quiet days. That means extra staff on Monday and empty workstations on Wednesday.
With GreenChoice, customers choose a delivery day at checkout that aligns with existing carrier routes. This spreads orders across the week and flattens the Monday peak.
For larger retailers, there's an added layer: multiple carriers with different pickup times. The moment you print a label (and pack the parcel) depends on when the carrier picks up. Carrier A picks up at 14:00, carrier B at 17:00. Your warehouse needs to group orders per carrier and have them ready at the right time.
Larger retailers deliberately work with multiple carriers, not just for better rates, but also to relieve pressure on the warehouse process. Multiple pickups per day, or a carrier's stand-trailer at the door, means less warehouse space taken up by labelled parcels waiting for collection. The label process is directly tied to your warehouse planning and space utilisation.
What's on a shipping label?
Every shipping label contains fixed elements, regardless of carrier:
- Carrier logo and service type: which carrier and service (express, standard, economy)
- Barcode(s): unique identification of the shipment. Carriers use 1D barcodes (linear) and/or 2D barcodes (QR code or data matrix)
- Tracking number: the unique code to track the shipment through the network
- Sender details: name, address, country
- Recipient details: name, address, postcode, country, phone number
- Weight: stated or measured weight
- Routing code: sorting code for the sorting centre (determines the parcel's route)
- Service codes: optional features like signature on delivery, evening delivery, fragile
For international shipments outside the EU, the label may contain additional information, depending on the carrier:
- Customs information: HS codes, value, country of origin
- CN22/CN23: some carriers support CN22/CN23 and attach it to or alongside the shipping label. Whether this is possible depends on the carrier
- EORI number of the sender
Additionally, labels increasingly contain information that drives or supports warehouse operations:
- Sorting information: which dispatch lane or dock the parcel should go to (1st dispatch, 2nd dispatch, express line). The barcode on the shipping label is often used for this
- Reference/order number: links to your WMS or ERP so you can trace which order each parcel belongs to
- Ship date: which day should the shipment go out? With GreenChoice, the customer chooses a delivery day, and the WMS system ensures the order is packed and labelled on the right day. Sometimes the ship date is also printed on the label
- Multi-colli sequence number: for orders with multiple parcels, the label indicates which collo it is (e.g. 2/3)
The label isn't just a document for the carrier, it's the link between your order, your warehouse and the carrier.
3 ways to create shipping labels
But first: when do you create the label?
Most webshops create the shipping label only after the parcel is packed. That seems logical, but it's slower than necessary. If you create the label as soon as the order comes in through the checkout, you can work ahead. The labels are already waiting in your ERP or WMS. Once the order is packed, you stick the label on without waiting for an API call to the carrier. The result: a faster warehouse process. And as a bonus, you become less dependent on the uptime of the carrier or shipping platform. Because virtually all shipping labels for the day have already been created and are ready to go, an outage no longer impacts your daily operations.
1. Manually via carrier portal
Log in to the carrier's website, enter address details and print a label. Suitable for 1-5 shipments per day. Downside: separate portal per carrier, no automation, error-prone.
2. Via a shipping platform (MyWuunder)
Orders flow automatically from your webshop to the platform. Per order you select (or let the platform auto-select) the carrier and service. Labels are generated in batch. Suitable for 10-500+ shipments per day.
With Wuunder you book via 300+ carrier connections from a single screen. Labels, customs documents and tracking are created automatically. Available via MyWuunder or via plugins for Shopify, WooCommerce, Magento and Shopware. View all integrations.
3. Via API
For developers and businesses with their own WMS/ERP. You send an API request with order data and receive a label PDF plus tracking number. Fully automated, no manual steps. Wuunder's REST API supports all 300+ carrier connections via a single integration. One API call for label + customs documents + tracking.
Custom labels for non-carrier shipments
Not every order goes via an external carrier. Customers picking up their order in your own store, orders delivered by your own transport organisation, or shipments that need a temporary label during the warehouse process: with Wuunder you can also generate custom labels. This way your entire order flow runs through one system, regardless of how the shipment leaves your building.
Scan & Print: scan packing slip, print label
In a busy warehouse you want as few clicks as possible. With Scan & Print you scan the barcode on the packing slip and the shipping label prints immediately. No screens, no choices, no waiting.
There are two ways to set this up:
- With Wuunder at your packing station: you use your own packing slips with a barcode. Wuunder runs at the packing station in your warehouse. Scan the packing slip, the label rolls out of the printer
- With your own WMS: your WMS sends the label request to Wuunder via the API and prints the label itself. You don't need to do anything in MyWuunder at all
In both cases the shipping label has already been created based on the order data (see above). The scan only triggers printing, not creation. That's what makes the process lightning fast.
Important: Scan & Print is designed so that a shipping label can only be printed once. If an order consists of multiple colli, the first scan prints label 1, the second scan prints label 2. Scan again after that and you get a warning that all labels have already been printed. This prevents accidentally shipping an order twice.
Handover list: proof of pickup
After printing all labels, you generate a handover list in MyWuunder per location and per carrier. You hand this list to the driver at pickup. This gives you proof of which shipments you handed over. The list also serves as an internal check: does the number of parcels match what you prepared?
Applying labels: how to avoid problems
A well-printed label is only half the job. How you apply the label determines whether the carrier can scan it:
- Apply the label to the top of the parcel or one of the two longest sides
- Apply the label flat, not folded over an edge
- Never apply tape over the barcode
- Remove all old barcodes still on the packaging
- Do not enlarge or reduce the label when printing
- Tip: put a copy of the shipping address inside the packaging as backup, in case something happens to the label
Batch printing: multiple labels at once
At more than 10 shipments per day, batch printing is essential:
- Select multiple orders in MyWuunder or via the API
- Generate all labels at once as a combined PDF
- Print via a label printer (Zebra, Brother, Dymo) or A4 printer
- Packing slip and label together in a single workflow
Wuunder supports standard A6 labels (10x15 cm) accepted by virtually all carriers, plus carrier-specific formats where needed.
Carrier API's changes: why you don't want to think about this
Every carrier has its own label specifications: supported formats (PDF, ZPL, PNG), dimensions (A6, 10x21), and requirements for barcode type and routing codes. These specifications change regularly. Some carriers only support PDF, others only ZPL in a specific size. Others generate native ZPL that needs to be converted to PDF if you don't have a thermal printer.
With multiple carriers this quickly becomes a maintenance problem. Wuunder handles it: the platform automatically generates the correct label format per carrier in the specification the carrier requires. No conversion or tracking of specs on your end.
Automation: from order to label in 0 clicks
With Wuunder you automate the entire process:
- Order arrives from your webshop, WMS or ERP
- PuzzlPack calculates the possible packaging combinations
- Based on the possible packaging options, the cheapest transport service is automatically selected based on destination, weight, dimensions and service preference
- Label + commercial invoice are generated if no paperless customs is offered by the carrier
- Tracking number is sent back to your webshop, WMS or ERP system
- Pickup is scheduled with the carrier if you want to send an incidental express shipment, for example
No manual steps. No portals. One integration for 300+ carrier connections.
Labels and international shipping
For shipments outside the EU, Wuunder automatically generates the required customs documents alongside the shipping label:
- Commercial invoice with HS codes, value and country of origin
- CN22/CN23 for postal shipments
- Paperless customs with DHL Express and FedEx: documents submitted digitally, nothing to print. No more sticking plastic pouches with commercial invoices on the parcel, which significantly speeds up your warehouse process
- Mandatory labelling of heavy parcels: in the Netherlands, several carriers require extra stickers on heavy parcels. For shipments to Germany, a legal requirement has been in effect since 1 January 2025: parcels weighing 10-20 kg and >20 kg must carry a separate weight marking. Many webshops are unaware of this
- Additional carrier requirements: some carriers have extra requirements for the shipment. For example, DPD Express requires special tape so DPD can more easily identify which shipments are urgent
Return labels
A return label follows the same logic as a shipping label, but in reverse. There are three common methods:
- Return label in the box: you generate the return label with the outbound shipment and include it in the parcel. The customer sticks the label on the box and drops it off. Simple for the customer, but you generate labels for returns that may never happen
- QR code via return portal: the customer registers the return via a return portal and receives a QR code. At the pickup point the label is printed on the spot. No printer needed for the customer, and you only generate labels for actual returns
- Return label on demand: the customer requests a return label and prints it at home. Less modern but still common
With Wuunder Returns you offer your customers a branded return portal where they register their own return. The customer can choose between exchanging or returning, which reduces the number of actual returns.
Difference between shipping label, packing slip and waybill
Three documents that are often confused:
- Shipping label: sits on the outside of the parcel and directs the carrier. Contains tracking barcode, routing code, sender and recipient. The label is what sorting centres and couriers scan
- Packing slip: describes the contents of the parcel for the recipient. Sits in or on the parcel. Not intended for the carrier but for the customer and the warehouse
- Waybill: the transport document that records the legal terms of the shipment. For parcel transport the waybill is often digitally embedded in the label. For pallet and freight transport it is a separate document
Shipping label maintenance: why this isn't a problem with Wuunder
Every carrier determines its own label specification: layout, barcode type, required fields, routing codes and service markings. These specifications change as carriers update their sorting network or technology. With one carrier that's manageable. With eight carriers across three countries you maintain eight separate specifications that change on eight different schedules. A single carrier brand can even have multiple divisions with different systems and label requirements.
Wuunder maintains the label specifications and booking integrations for all 300+ carrier connections. Your system connects once, and the label that comes out always matches the carrier's current specification. If a carrier changes their APIs, Wuunder updates it without you having to do anything.
Discover the possibilities
We'd love to show you during a demo how Wuunder transforms your daily workflow.
Q: How do I create a shipping label?
A: Via a shipping platform like Wuunder, this can be done through a portal, via the API, or via a webshop plugin for e.g. Shopify, WooCommerce or Magento. With Wuunder you book via 300+ carrier connections.
Q: Can I print labels for multiple carriers at once?
A: Yes. In MyWuunder you select multiple orders and generate all labels as a single PDF or ZPL, regardless of which carrier is selected per order. If you use a WMS or ERP system, you can stage labels in those systems so you don't need to book with the carrier before printing labels. Of course, you can also book multiple labels simultaneously with many carriers.
Q: Which printer do I need?
A: A thermal label printer (such as Zebra) is the standard for professional shipping operations. Thermal printers use no ink, are fast and reliable at high volumes. Wuunder supports ZPL output for direct control from your WMS or the MyWuunder environment. If the carrier doesn't offer ZPL, we provide PDF only. If the carrier only provides ZPL, we automatically create a PDF version as well.
Q: Are customs documents automatically included?
A: Yes. For non-EU shipments, Wuunder automatically generates the commercial invoice. With paperless carriers (DHL Express, FedEx), documents are submitted digitally to the carrier and don't need to be attached to the shipment.
Q: Can I create labels via the API?
A: Yes. Wuunder's REST API returns a label (ZPL or PDF), tracking number and commercial invoice per request. One API integration for all 300+ carrier connections. You can book using the carrier's service codes or ask Wuunder for the cheapest or fastest service. Of course, you can also request all available services for an order and then create labels.
Q: What if I created a label but the shipment doesn't go?
A: You can cancel the shipment in MyWuunder or via the API. Note: this cancels the booking in Wuunder, but not automatically with the carrier. If the shipment has already been registered with the carrier, contact the carrier directly to cancel the pickup.
Q: Does Wuunder validate address data before creating the label?
A: Yes. Wuunder checks whether the postcode and country meet the carrier's requirements. Without a correct postcode you cannot create a label. This prevents shipments from getting stuck at the carrier.
Q: Are special characters displayed correctly on the label?
A: Wuunder generates labels with the correct encoding for international characters (umlauts, accents, special characters). Some carriers handle encoding differently. If there's an issue with booking a shipping label, our team resolves it for you.