If you ship parcels in the UK, 4×6 thermal labels (also called 100×150mm) are the day-to-day standard for courier labels. This size suits most label layouts because it leaves clear space for addresses, barcodes, and tracking codes without shrinking scan areas.
This guide is written as a UK packing specialist buying resource. It explains what to look for when buying 4×6 direct thermal shipping labels in the UK, how to compare suppliers properly (including VAT pricing), how many labels you actually need, and how to avoid the common label problems that slow down dispatch.
If you want to go straight to stock, start with the main range: thermal labels, and the core product most sellers standardise on: white 4×6 thermal labels (100×150mm).
Part of a UK label size cluster: this pillar guide is supported by two related posts that go deeper on specific courier workflows: Royal Mail 4×6 direct thermal labels and DPD 4×4 vs 4×6 label sizes.
1) What Are 4×6 Thermal Labels? (100×150mm Direct Thermal Explained)
Before you buy, it helps to understand the terms sellers see online. Many “wrong order” issues happen because a listing says 4×6, but the spec is not stated clearly (core size, adhesive, label count, or paper type).
4×6 vs 100×150mm – are they the same?
Yes. 4×6 inches is the common name. 100×150mm is the metric measurement used by UK courier systems and shipping platforms. When you see “100×150 shipping labels”, it normally means standard 4×6 thermal labels.
What “direct thermal” means (no ribbon needed)
Direct thermal labels print using heat from the printer head. You do not need ink, toner, or ribbon. That makes them fast for daily dispatch and easier to cost per shipment.
Direct thermal vs thermal transfer (quick, practical difference)
Thermal transfer uses a ribbon and is often chosen for long-life labelling. For shipping labels, most UK sellers use direct thermal because it is simpler and cost-effective for short-term label life.
Roll vs fanfold labels (which should you pick?)
Most sellers use roll labels because they fit standard desktop printers neatly. Fanfold labels feed from a stack and can be useful in high-volume workflows where you want fewer roll changes. If you prefer stacked feeding, see 4×6 fanfold thermal labels.
2) Why 4×6 (100×150mm) Is the UK Standard for Courier Labels
Most sellers who search “buy 4×6 thermal labels UK” want one simple outcome: labels that scan cleanly and stay stuck until delivery. The 4×6 format helps with both.
More space for barcodes and tracking codes
Courier labels often include multiple codes and routing info. The 4×6 layout gives enough space so barcodes can remain large and easy to scan.
Works across common UK courier workflows
Royal Mail, DPD, Evri, and UPS style label layouts commonly output in a 100×150mm format. If you want the safest “one label size” approach, 4×6 is the default.
When 4×6 is not the best choice
Some DPD workflows and certain carton sizes use a smaller label. If you are deciding between sizes, use: DPD 4×4 vs 4×6 direct thermal labels.
3) Key Features of a Proper 4×6 Shipping Label (What You Should Expect)
This is the checklist UK sellers should use when comparing suppliers. If a listing does not state these clearly, it is hard to judge quality and compatibility.
- Size: 4×6" (100×150mm) — UK standard for courier labels
- Pack size: 12 rolls
- Label count: 500 labels per roll (6,000 labels per pack)
- Paper type: direct thermal economy paper — no ribbon needed
- Perforation: between each label for clean tear and quick handling
- Adhesive: hot-melt adhesive for strong bonding on cardboard, films, and plastics
- Print clarity: sharp print for barcodes and tracking codes
- Use case: designed for short-term use (shipping, picking, returns)
- Printers: works with Zebra GK420, Citizen CL-S, and TSC 4" thermal printers
- Colour options: white, red, blue, yellow, orange
Shop the full range here: thermal labels. Most sellers start with white 4×6 labels and add colour options for internal control once the dispatch process grows.
4) Who Uses 4×6 Thermal Labels in the UK?
These labels are used anywhere that speed, barcode accuracy, and reliable adhesion matters. This section also helps you build a complete dispatch setup with the right packaging.
Marketplace sellers (eBay and multi-channel)
Marketplace sellers need fast packing and fewer mistakes. A common setup is white 4×6 labels + the right mailer for the order type.
Shopify and ecommerce stores
Shopify stores often batch print labels, then pack in waves. Reliable labels reduce reprints and help avoid scan issues at courier depots.
Warehouse and fulfilment teams
Fulfilment teams often use colour coding to manage returns, picking waves, and priority orders. This is where coloured labels and coloured mailers can reduce handling time.
Packaging that sellers buy alongside thermal labels
- Mailing bags for lightweight parcels
- Cardboard boxes for protection and stacking
- Packaging tape for strong sealing and cleaner handover
If you use coloured mailers for sorting or brand presentation, these are the main UK ranges: grey, blue, green, pink, purple.
5) Comparing UK Thermal Label Suppliers (What Usually Goes Wrong)
This section is here because “cheap labels” often become expensive once you factor in wasted rolls, relabelling, and packing delays. You do not need the cheapest label. You need the label that performs every day.
Marketplaces: price looks good, specs are often unclear
Common issues on marketplaces include pricing shown ex VAT, rolls that are not the label count you expected (500 vs 1,000), and listings that do not state adhesive type or core size. Some imports also arrive with inconsistent roll winding, which increases the chance of jams.
Wholesalers: reliable, but price per roll can be higher
Wholesalers can be consistent, but pricing can be less competitive unless you meet larger order thresholds. Some sellers also find the best deals are tied to account pricing, not the public price.
Specialist suppliers: clearer specs, repeatable stock
Specialist suppliers usually publish the spec clearly (label count, adhesive, perforation, core size, and printer compatibility). For busy dispatch, that repeatability matters.
Quick comparison table (what matters on a packing bench)
| What matters | What you want | What can go wrong |
|---|---|---|
| VAT pricing | VAT-inclusive pricing shown clearly | VAT added at checkout |
| Label count | 500 or 1,000 per roll (stated clearly) | Unexpected label count |
| Adhesive | Hot-melt adhesive for cartons + films | Weak adhesive, peeling corners |
| Perforation | Clean tear between labels | Messy tear, slow handling |
| Roll consistency | Even winding and feed | Jams and misfeeds |
If you want a UK stock range with clear specs, use: thermal labels. If you want the main product most sellers start with: white 4×6 thermal labels.
6) How Many Labels Are in a Roll (And How Many You Should Buy)
For daily dispatch, the practical question is not just “what size do I need?” It is “how many labels will I get, and how long will that last?”
Typical label count for 4×6 rolls
Many 4×6 thermal label rolls are sold as 500 or 1,000 labels per roll. Always check the product page for the confirmed roll count. For our core UK dispatch packs, the standard format is 12 rolls with 500 labels per roll, giving 6,000 labels per pack.
Simple buying guidance by order volume
- Low volume: occasional shipping — keep one pack in stock so you do not run out mid-week
- Daily dispatch: keep at least one spare roll per station and reorder before the last box is opened
- Warehouse scale: standardise your label spec across stations to reduce errors and ordering mistakes
For a dependable baseline, start with: white 4×6 (100×150mm) thermal labels.
7) Cost Breakdown: What 4×6 Thermal Labels Really Cost Per Shipment
Thermal labels are one of the lowest costs in dispatch, but they impact speed and error rates. The easiest way to compare suppliers is cost per label and cost per 100 shipments.
Cost per label (simple method)
Take the pack price and divide by total label count. For example, a 12-roll pack with 500 labels per roll equals 6,000 labels total. That gives you a clear cost per label.
Cost per 100 shipments
Once you know cost per label, multiply by 100. This gives a realistic “weekly shipping” cost estimate for many small and mid-size UK sellers.
Why VAT-inclusive pricing matters
When VAT is clear up front, you can cost shipments properly and avoid margin surprises at checkout — especially if you are comparing a supplier price to a marketplace listing.
The hidden cost of cheap labels
Weak adhesive can peel off cardboard boxes. Poor print coating can reduce barcode clarity. If you have to relabel parcels or reprint batches, the “cheap” label quickly becomes expensive.
8) Common Problems UK Sellers Have With 4×6 Labels (And How to Avoid Them)
This section is based on real packing bench issues. If you fix these, you reduce waste and speed up dispatch.
Labels peeling off cartons or mailers
This is usually an adhesive issue or a surface issue. Hot-melt adhesive is designed to bond strongly on cardboard, films, and many plastics, but you still need to apply to a clean, dry surface.
Barcode scan failures
Scan issues often come from low print contrast, creased labels, or labels applied over edges. A sharp print surface and flat application improves scan reliability.
Printer jams and misfeeds
Inconsistent roll winding, damaged roll edges, or incorrect gap calibration can cause misfeeds. Storing rolls properly and using consistent stock reduces this risk.
Wrong core size
Many 4-inch desktop printers accept a 25mm (1 inch) core. If you order the wrong core size, the roll may not fit correctly, which leads to feed problems.
9) How to Apply 4×6 Thermal Labels So They Stay Stuck (Quick Method)
This is a small section that prevents a lot of courier issues. Even a good label can fail if it is applied badly.
- Apply to a clean, dry surface (dusty cartons reduce adhesion)
- Place the label on a flat face, not over corners or edges
- Press firmly, including corners, to bond the adhesive
- Avoid taping over barcodes (it can cause glare and scan failures)
- Seal parcels with packaging tape, but keep the label area clear
If you ship in poly mailers, choose a smooth label placement area on your mailing bags and press firmly to reduce corner lift.
10) Technical Specifications to Check Before You Buy
Elite buyers’ guides do not skip specs. Specs prevent ordering mistakes and reduce printer downtime.
Perforation and label gap consistency
Clean perforation between labels improves handling speed and helps the printer detect label boundaries consistently.
Core size and roll diameter
Check core size (often 25mm / 1 inch for many desktop printers) and ensure roll diameter fits your printer housing.
Print resolution compatibility (203dpi vs 300dpi)
Most shipping labels print well at 203dpi. Higher resolution helps small text, but coating quality and correct printer settings still matter more for barcode clarity.
Short-term use design
Shipping labels are designed for short-term logistics and handling. Store properly and avoid heat to keep print performance consistent.
11) Adhesive Explained: Why Hot-Melt Matters for UK Shipping
Adhesive is the difference between a label that stays put and a label that peels in transit.
Cardboard cartons (including recycled board)
Recycled cartons can be textured or dusty. A strong hot-melt adhesive helps the label bond properly and reduces corner lift.
Films and plastics (mailers and wrapping)
Film surfaces can be slippery, so cheap labels often fail here. Hot-melt adhesive is a safer option for sellers using mailers and poly surfaces.
Cold and damp handling
Cold handling conditions can reduce tack on weak adhesives. Choosing a shipping-grade adhesive improves everyday performance during courier handling.
12) Storage and Handling: Keep Labels Printing Cleanly
Avoid heat and direct sunlight
Direct thermal material can react to heat. Keep rolls away from hot warehouse zones and sunny windows.
Store dry and sealed
Humidity can affect both adhesive and feeding. Keep rolls sealed until needed.
Avoid crushing rolls
Deformed rolls increase misfeed risk. Store cartons flat and do not over-stack heavy boxes on top.
13) Choosing the Right Dispatch Setup (Small Seller → Warehouse)
This section helps buyers choose a setup that suits their volume, without overbuying or underbuying.
Setup 1: Small seller (occasional parcels)
Goal: simple, reliable label printing. Use white 4×6 labels and pair with mailing bags for lightweight orders.
Setup 2: Growing ecommerce (daily dispatch)
Goal: speed and fewer errors. Keep spare rolls ready, use cardboard boxes for fragile items, and seal consistently with packaging tape.
Setup 3: Warehouse or multi-station packing
Goal: standardise and colour-code. Keep one label spec across stations, add colour options for routing, and use coloured mailers for sorting: grey, blue, green, pink, purple.
14) Why 4×6 Thermal Labels Beat A4 Labels for UK Dispatch
Faster packing
Thermal labels print one-by-one, ready to peel and stick. A4 labels often mean printing sheets, aligning, peeling, and sometimes trimming.
Better cost control
Direct thermal means no ink or toner. For many sellers, that reduces ongoing running costs and keeps dispatch predictable.
Cleaner barcodes
A flat thermal label is less likely to crease compared to a label taped over or folded around edges. That improves scan reliability.
15) Printer Compatibility: What Printers Use 4×6 Labels?
These 4×6 labels are used day-to-day with:
- Zebra GK420d / GK420t
- Citizen CL-S series
- TSC DA210 / DA220 and TE series
They are also suitable for other 4" direct thermal printers that accept 100mm-wide media. If you are unsure, start with the most common format: white 4×6 (100×150mm) labels.
16) Common Uses for 4×6 Thermal Labels (Beyond Courier Shipping)
- Courier shipping labels (Royal Mail, DPD, Evri, UPS)
- Warehouse picking, packing, and returns
- Product identification and barcodes
- Order batching and colour-coded workflows
Royal Mail-specific context is covered in: Royal Mail 4×6 direct thermal labels guide.
17) 4×6 vs 4×4 Labels: Which Should You Buy?
Choose 4×6 for the safest UK standard
If you want maximum compatibility, 4×6 is the default choice for courier labels.
Choose 4×4 for specific workflows
If your workflow clearly uses 4×4, compare sizes here: DPD 4×4 vs 4×6 direct thermal labels.
18) Colour Options: White vs Red vs Blue vs Yellow vs Orange
Most sellers use white labels for courier shipping because they maximise contrast. Colour labels are popular for internal control, returns, and warehouse routing.
White (standard courier printing)
Start with white 4×6 labels for day-to-day shipping.
Red, blue, yellow, orange (colour-coded workflows)
Use colours for returns, picking waves, priority orders, and internal sorting:
For a full view of sizes and colours, use: thermal labels.
19) UK Eco and Recycling Notes
Thermal labels are typically paper face stock with adhesive backing. Recycling guidance can vary by local council, but a simple best practice is to remove labels from cardboard where possible before recycling, especially for warehouse waste.
If you ship in cartons daily, choosing the right size reduces waste and tape use. Browse: cardboard boxes and seal reliably using packaging tape.
20) Where to Buy 4×6 Thermal Labels in the UK (Fast, Consistent, UK Stock)
If your goal is smooth dispatch, the buying decision is simple: choose a supplier that states the spec clearly, keeps UK stock, and delivers repeatable quality so you are not troubleshooting labels mid-shift.
What UK sellers get when ordering from Mr Bags
- UK standard 4×6 (100×150mm) courier label size
- Pack size: 12 rolls
- 500 labels per roll (6,000 per pack)
- Direct thermal paper (no ribbon needed)
- Perforation between labels for quick handling
- Hot-melt adhesive for cartons, films, and plastics
- Sharp print for barcodes and tracking codes
- Colour options for warehouse workflows
Start here: browse the full range: thermal labels. If you want the standard option most UK sellers use, go straight to: white 4×6 thermal labels (100×150mm).
21) Thermal Labels Resource Centre (UK Guides That Support This Page)
This blog is the pillar guide for UK sellers buying 4×6 shipping labels. These two supporting guides strengthen the topic cluster and help you choose based on courier workflow:
- Royal Mail 4×6 direct thermal labels: what UK sellers need after the 2026 change
- DPD 4×4 vs 4×6 direct thermal labels: UK shipping guide
If you standardise your label size, choose a repeatable spec, and keep label stock in place, your dispatch becomes faster, cleaner, and easier to scale.
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