The best cardboard boxes for international shipping are new double wall boxes, packed so the contents cannot move, sealed along every seam with packing tape, and carrying the paperwork in a documents enclosed wallet on the outside. Fragile goods should be double boxed, which means a packed inner box cushioned inside a larger outer box.
We cover why double wall board suits an export parcel, which box size to pick, how to double box breakables, how to tape the box, where the documents go and how to label it. We also say when a cardboard box is the wrong packaging, and what the materials cost per parcel. This guide does not cover customs rules, duty, prohibited items or carrier size and weight limits. Those change by carrier and by country, so check them with your carrier and the destination country before you pack anything.
In This Guide
- Quick picks for packing an international parcel
- Why use heavy duty boxes for international shipping?
- Which size box should you use for an international parcel?
- When should you double box fragile goods, and how do you do it?
- How do you seal a box for international shipping?
- Where do the documents go on an international parcel?
- How should you label an export box?
- When is a cardboard box not enough for export?
- How much should you buy, and what does it cost per parcel?
- Frequently Asked Questions
Quick picks for packing an international parcel
These three cover the box, the seal and the paperwork on most parcels going abroad.
Best for the box itself
Double Wall Cardboard Boxes
Heavy duty corrugated boxes with two layers of fluting, for heavier, fragile or high value goods.
- 11 sizes, 9 x 6 x 6" to 24 x 24 x 24"
- Sold per box, minimum 5 for most sizes
- Arrive flat packed
From £0.59 ex VAT (£0.71 inc VAT)
Choose sizeView product
Best for paperwork on the outside
Documents Enclosed Wallets
Clear self-adhesive pouches that hold the invoice or packing list on the outside of the parcel.
- A5, A6 and A7 sizes
- Plain or printed Documents Enclosed
- Boxes of 1000 wallets
From £15.00 ex VAT (£18.00 inc VAT)
Choose sizeView product
Best for sealing the seams
Brown Packing Tape
Buff polypropylene packing tape that matches brown cartons, in five roll options.
- Packs of 6 rolls
- 48mm x 66m standard roll, 42 micron acrylic
- Proloc 72mm x 66m wide roll for bigger, heavier cartons
From £4.50 ex VAT (£5.40 inc VAT)
Choose sizeView productWhy use heavy duty boxes for international shipping?
Use heavy duty boxes for international shipping because the parcel is usually handled more times, travels further and spends longer stacked under other freight than a parcel staying in the UK. A double wall cardboard box has two layers of fluting in the board. Our product page describes that board as stronger than single wall and better at stacking, and an export parcel needs both.
Our double wall boxes come in 11 sizes from 9 x 6 x 6" (229 x 152 x 152mm) to 24 x 24 x 24" (610 x 610 x 610mm), sold per box from £0.59 ex VAT (£0.71 inc VAT). The minimum order is 5 boxes for most sizes and 90 boxes for the 24 x 24 x 24" size. They arrive flat, so a stack takes little room until you make them up.
- Use a new box. A box that has already been through the post has softened corners and old creases. Keep reused boxes for local jobs.
- Use double wall for anything heavy, fragile or valuable. The second layer of fluting is there for those loads.
- Single wall still has a place. A light, soft, unbreakable item such as folded clothing can travel in a single wall box, from £0.35 ex VAT (£0.42 inc VAT). It also works well as the inner box when you double box.
If you want the full comparison of the two board types, our guide to single wall vs double wall cardboard boxes goes through it. For choosing strong boxes in general, including what makes a box heavy duty, see heavy duty cardboard boxes: how to choose and pack strong boxes.
We cannot give you a weight limit. We do not publish a maximum load for our boxes, and your carrier sets its own weight and size limits for each service and destination. Check those limits with the carrier before you choose a box.
Which size box should you use for an international parcel?
Pick the smallest box that holds the item plus its cushioning on every side. Many carriers price international parcels on size as well as weight, so empty space can cost you twice: once in void fill and again in postage. Ask your carrier how it measures and prices parcels for your destination, then choose the box.
Heavy items belong in smaller boxes. A small box full of metal parts is easier to lift and less likely to be dropped than a large box with the same parts rattling around in one corner. Our product page gives the same advice for moving boxes, and it applies just as much to export.
| Double wall size | In millimetres | Typical use for an export parcel |
|---|---|---|
| 9 x 6 x 6" | 229 x 152 x 152mm | Small, heavy parts. Also a good inner box for double boxing. |
| 12 x 9 x 6" | 305 x 229 x 152mm | A4 documents, books and flat goods with padding round them. |
| 12 x 9 x 9" | 305 x 229 x 229mm | A4 sized goods with more depth, or an outer box for a 9 x 6 x 6" inner. |
| 12 x 12 x 12" | 305 x 305 x 305mm | A general cube for one medium item with cushioning. |
| 14 x 14 x 14" | 356 x 356 x 356mm | Medium items, or the inner box of a larger double boxed parcel. |
| 18 x 12 x 11" | 457 x 305 x 279mm | Longer items, or an outer box for a 12 x 9 x 6" inner. |
| 18 x 18 x 18" | 457 x 457 x 457mm | Bulky but lighter goods, or an outer box for a 12 or 14 inch cube. |
| 23 x 12 x 15" | 580 x 305 x 377mm | Long items that need space at both ends. |
| 24 x 18 x 12" | 610 x 457 x 305mm | Wide, shallow goods. |
| 24 x 18 x 18" | 610 x 457 x 457mm | Large, light items, or an outer box for an 18 x 12 x 11" inner. |
| 24 x 24 x 24" | 610 x 610 x 610mm | The largest size. Minimum order 90 boxes. Check carrier size limits first. |
When should you double box fragile goods, and how do you do it?
Double box anything that would break or dent if the outer box took a hard knock: glass, ceramics, electronics, instruments and items with a finish you cannot repair. Double boxing means packing the item in one box, then floating that box inside a larger one with cushioning between the two. A blow to the outer box is absorbed by the cushioning before it reaches the inner box.
A common rule of thumb is a gap of about 50mm (2 inches) between the inner and outer box on every side. Treat that as a starting point. A heavy item needs firmer cushioning that will not flatten under its weight, and a very delicate one may need more room.
- Wrap the item. Wrap it in bubble wrap so no hard surface is exposed, and tape the wrap closed. If there are several items, wrap each one separately so they cannot touch.
- Pack the inner box. Put the wrapped item in a box that fits it closely and fill any gaps. Close the box and shake it gently. If you feel or hear movement, open it and add more fill.
- Seal the inner box. Tape it shut as if it were going out on its own.
- Line the base of the outer box. Put a layer of cushioning in the bottom of the outer box, thick enough to match the gap you are leaving on the sides.
- Centre the inner box. Sit the inner box in the middle and pack cushioning down all four sides so it cannot slide.
- Cover the top. Add a final layer so the flaps of the outer box close onto cushioning with a little resistance, then seal the outer box.
For the gap between the boxes, large bubble wrap works well. It has 25mm bubbles, and our product page notes that it doubles as void fill when you scrunch it into gaps. Rolls are 50m long in 300mm or 500mm widths, from £9.00 ex VAT (£10.80 inc VAT) per roll. Loose fill is the other common choice. EcoFlo biodegradable packing peanuts pour in and settle round the inner box, and come in 5 cubic feet bags from £13.00 ex VAT (£15.60 inc VAT). Our guide to void fill compared sets out how air cushions, peanuts, paper and bubble wrap differ.
Best for cushioning between two boxes
Large Bubble Wrap
25mm bubbles that cushion bulky or heavy items and fill the space around them in the box.
- 50m rolls
- 300mm or 500mm wide
- Sold per roll, minimum one roll
From £9.00 ex VAT (£10.80 inc VAT)
Choose sizeView product| Inner box | Outer box | Gap on each side (length, width, height) |
|---|---|---|
| 9 x 6 x 6" | 12 x 9 x 9" | About 1.5" (38mm) all round |
| 12 x 9 x 6" | 18 x 12 x 11" | About 3", 1.5" and 2.5" |
| 12 x 12 x 12" | 18 x 18 x 18" | About 3" (76mm) all round |
| 14 x 14 x 14" | 18 x 18 x 18" | About 2" (51mm) all round |
| 18 x 12 x 11" | 24 x 18 x 18" | About 3", 3" and 3.5" |
Those gaps are worked out from the listed sizes, so allow for the thickness of the board. Make up one inner and one outer box and check the fit before you pack a batch.
You do not always need two boxes. Sturdy goods that cannot break, such as clothing, books or boxed tools, are fine in one double wall box with the gaps filled. Double boxing costs a second box and often more postage, so keep it for things that would be expensive to replace. For general packing steps see how to pack a box for shipping.
How do you seal a box for international shipping?
Seal a box for international shipping by taping the centre seam and both edge seams on the top and the bottom, which makes an H shape on each face. One strip down the middle leaves the flap ends free to lift and catch on conveyors or other parcels. Taping the edges as well closes the box on all sides and stops dust and damp getting in through the gaps.
- Fold the bottom flaps, short flaps first, then the long flaps over them.
- Run one strip of tape along the centre seam, carrying it at least 50mm up each end of the box.
- Run a strip across each of the two edge seams where the flap ends meet the box sides.
- Pack the box, close the top flaps and repeat the same three strips on top.
- Press every strip down firmly with your hand so the adhesive grips the board, and add a second centre strip on a heavy box.
Brown packing tape is the usual choice on a brown carton. Ours is buff polypropylene tape in packs of 6 rolls, from £4.50 ex VAT (£5.40 inc VAT). The standard 48mm x 66m roll is acrylic adhesive on 42 micron film and suits most box sizes. For large or heavy cartons, the Proloc 72mm x 66m roll is wider, so each strip covers more of the seam and more of the board either side of it. If you seal a lot of boxes, the 48mm x 132m roll and the BigTape 48mm x 150m low noise roll need changing less often.
- Do not use string or cord. Loose ends catch in sorting machinery. Tape is enough.
- Cover or remove old labels and barcodes if you have to reuse a box, so scanners read only the new label.
- Strapping is a separate product. Some shippers add plastic strapping to heavy cartons. We do not stock strapping.
Clear tape seals just as well as brown. Our packing tape guide covers types and widths, and the full range is in the packing tapes collection.
Where do the documents go on an international parcel?
Paperwork that has to travel with an international parcel goes on the outside of the box in a clear, self-adhesive documents enclosed wallet, where staff can reach it without opening the parcel. Which documents are needed, how many copies and whether the carrier wants them on the box at all depends on the carrier, the service and the destination. Ask your carrier before you seal anything.
Documents enclosed wallets are clear pouches with a peel-off backing. You put the folded paperwork inside, peel the backing and press the wallet onto the box. They come plain or printed with the words Documents Enclosed, in three sizes, and are packed in boxes of 1000 from £15.00 ex VAT (£18.00 inc VAT).
| Wallet size | Outside measurement | What it holds |
|---|---|---|
| A5 | 225 x 165mm | A5 sheets flat or an A4 invoice folded once. The usual size for export paperwork that runs to several pages. |
| A6 | 158 x 110mm | An A4 sheet folded twice, or a single A6 packing slip. |
| A7 | 95 x 125mm | Till receipts, returns slips or A7 cards. |
- Stick the wallet on the largest flat face, next to the address label and clear of the tape seams, so it lies flat and nothing has to be cut to open the box.
- Keep it away from edges and corners. A wallet wrapped round a corner gets torn off.
- Choose printed wallets if you want handlers to see at a glance that paperwork is attached. Plain wallets do the same job with nothing printed on the front.
- Put a copy inside the box too. If the wallet is lost or damaged, a copy of the invoice and both addresses inside the parcel gives someone a way to identify it.
We have a separate guide to documents enclosed wallets that covers sizes, plain against printed and how to apply them, so look there for the detail.
We cannot advise on customs paperwork. The forms, declarations and commercial invoice details required for a destination are set by the carrier and by that country. Get them from your carrier or the relevant government guidance. A wallet only keeps the paperwork attached.
How should you label an export box?
Label an export box with one clear address label on the largest face, a return address, and any handling labels on the top and at least one side. Use one shipping label only. A second, older label or barcode on the box can send it to the wrong place, so remove or cover everything that does not belong to this journey.
- Flat and fully visible. Stick the address label flat on one face. Do not fold it over an edge or run tape across the barcode unless your carrier says that is fine.
- Full address in the format the destination uses. Include the postcode or its local equivalent, the country in capitals on the last line, and a contact phone number if your carrier asks for one.
- Return address on the outside, plus a duplicate of both addresses inside the box.
- Handling labels where they will be seen. Our product page suggests a fragile sticker on the top of the box and on at least one side, so it shows however the parcel is stacked.
Our warning labels come on rolls in two designs. Fragile labels measure 89 x 32mm with 1000 on a roll. Caution Heavy labels measure 148 x 50mm with 500 on a roll, and are meant to warn handlers about the weight before they lift. Rolls start from £10.00 ex VAT (£12.00 inc VAT), and you can order a single roll.
Best for handling warnings
Warning Labels
Self-adhesive parcel labels on rolls that ask handlers to take care with a package.
- Fragile 89 x 32mm, roll of 1000
- Caution Heavy 148 x 50mm, roll of 500
- Peel and apply by hand
From £10.00 ex VAT (£12.00 inc VAT)
Choose sizeView productA fragile sticker asks for care but cannot make anyone give it, and a handler in another country may not read English. Pack the parcel as though the label were not there, then add the label. Our post on fragile tape and fragile stickers goes into this in more detail. If you would sooner seal and mark the box in one go, fragile tape has the word FRAGILE printed along its length, in packs of 6 rolls from £5.50 ex VAT (£6.60 inc VAT).
We do not sell label printers or custom printed boxes, so a printed address or customs label has to come from your own printer or your carrier. Blank labels are in the labels collection.
When is a cardboard box not enough for export?
A cardboard box is not enough when the goods are too heavy or too awkward to be lifted by one person, when they are going by sea or air freight on a pallet, or when your carrier or customer specifies a crate or certified export packaging. In those cases you need a specialist export packer or your freight forwarder's advice.
We do not sell plywood crates, timber cases or export-certified packaging. Our range is stock corrugated boxes, tape, labels and protective materials, which cover parcels sent through courier and postal networks. That is what most small exporters and online sellers send.
- Machinery, engines and very heavy parts usually need a crate or a pallet. Ask your freight forwarder.
- Liquids, batteries, aerosols and anything classed as dangerous goods have their own packaging rules. Your carrier will tell you whether it accepts them at all and what packaging is required.
- Several cartons going together can be stacked on a pallet and wrapped. We stock pallet wrap for that, but pallets themselves, and the rules on them for a given destination, are a question for your forwarder.
If you are not sure whether a box will do, ring us on 0161 706 1246 or use the contact page.
How much should you buy, and what does it cost per parcel?
For a first run of international parcels, buy a small quantity of one or two box sizes, one pack of tape, one roll of bubble wrap and one box of wallets, then reorder in larger quantities once you know which sizes you use. Most of our products have volume pricing, so the price per box, roll or pack falls as you buy more. The tiers are shown on each product page.
| Item | Pack | From price | Rough cost per parcel at the from price |
|---|---|---|---|
| Double wall boxes | Per box, minimum 5 for most sizes | £0.59 ex VAT (£0.71 inc VAT) | One box, or two if you double box. Larger sizes cost more. |
| Brown packing tape | Pack of 6 rolls | £4.50 ex VAT (£5.40 inc VAT) | 75p a roll ex VAT. One roll seals many boxes. |
| Large bubble wrap | Per 50m roll | £9.00 ex VAT (£10.80 inc VAT) | 18p a metre ex VAT. |
| Documents enclosed wallets | Box of 1000 | £15.00 ex VAT (£18.00 inc VAT) | 1.5p a wallet ex VAT. |
| Warning labels | Per roll | £10.00 ex VAT (£12.00 inc VAT) | One roll covers hundreds of parcels. |
The box is the biggest cost on that list, and an oversized box also costs more to send. If you only send a parcel abroad now and then, you may not need wallets at all: ask your carrier whether a printed label alone is enough for your service.
Royal Mail Tracked 48 delivery is free on every order with no minimum, and orders placed by 2pm Monday to Friday leave our Manchester unit the same working day. If you are local, click and collect is free and usually ready within 2 hours, and we run same-day van delivery within 10 miles of Cheetham Hill. Every order comes with a VAT invoice. Regular exporters can apply for a trade account.
Frequently Asked Questions
What are the best cardboard boxes for international shipping?
New double wall cardboard boxes are the best choice for most international shipping. Double wall board has two layers of fluting, which makes the box stronger than single wall and better at stacking. Pack Solution sells double wall boxes in 11 sizes from 9 x 6 x 6" to 24 x 24 x 24", from £0.59 ex VAT (£0.71 inc VAT) per box.
Do I need to double box a parcel going abroad?
You need to double box a parcel going abroad only if the contents are fragile or costly to replace, such as glass, ceramics or electronics. Double boxing puts a packed inner box inside a larger outer box with cushioning between them, and a gap of about 50mm on each side is a common rule of thumb. Sturdy goods such as clothing or books are fine in a single double wall box with the gaps filled.
Where should I put the customs paperwork on a parcel?
Paperwork that travels with a parcel normally goes in a clear documents enclosed wallet stuck to the outside of the box, on the same face as the address label and clear of the tape seams. Which documents are required, and whether they need to be on the box at all, depends on your carrier and the destination country, so check with your carrier first. Putting a copy of the invoice and both addresses inside the box is a sensible backup.
What tape should I use to seal an export box?
Use polypropylene packing tape, brown or clear, to seal an export box. Tape the centre seam and both edge seams on the top and bottom so the tape forms an H on each face. Pack Solution brown packing tape comes in packs of 6 rolls from £4.50 ex VAT (£5.40 inc VAT), including a wide Proloc 72mm x 66m roll for bigger, heavier cartons.
Do fragile labels work on international parcels?
Fragile labels ask handlers to take care with an international parcel, but fragile labels do not protect the contents and may not be read in every country. Pack the parcel so it would survive without the label, then add fragile labels to the top and at least one side. Pack Solution Fragile labels measure 89 x 32mm and come on rolls of 1000.
Does Pack Solution sell export crates or certified export packaging?
Pack Solution does not sell plywood crates, timber cases or export-certified packaging. Pack Solution sells stock corrugated boxes, packing tape, labels, documents enclosed wallets and cushioning for parcels sent through courier and postal networks. If your carrier or freight forwarder specifies a crate or certified packaging, you will need a specialist export packer.
