Custom Mailer Boxes Made to Your Inside Size
We make mailer boxes to the inside size you send, in brown kraft or white-lined corrugated board, plain or printed. Tell us what you post and which postal band it has to fit, and a custom quote comes back within one working day.
Six mailer box styles, each folded from one sheet
The style is really the closure: how the lid holds and which end opens. Choose the one that suits the product and the speed you pack at.
Tuck TopLid tucks into the front; the standard ecommerce mailer.From £0.25 a box
Ear LockSide ears lock the lid shut without tape.From £0.25 a box
Side Loading Tab LockLoads from the side, tabs lock; flat goods and prints.From £0.25 a box
End OpenOpens at the short end; books and boxed sets.From £0.25 a box
Double Sided PrintedFull print outside and inside the lid and base.From £0.25 a box
Folding SmallSmall plain mailers that fold up in seconds.From £0.25 a boxEvery mailer box and mailer we make
Fourteen corrugated boxes and two soft mailers, all made to order. Each card shows what the box does best; open one for sizes, board and print.
Tuck Top Mailer BoxesRoll-over front, tuck-in lid, prints inside and outFrom £0.25 a boxEar Lock Mailer BoxesTape-free close for unboxing on cameraFrom £0.25 a boxSide Loading Tab Lock MailersSlide in from the side, lock with two tabsFrom £0.25 a boxEnd Open Mailer BoxesShort-end opening for books, frames and setsFrom £0.25 a boxDouble Sided Printed Mailer BoxesPattern or message inside, brand on the outsideFrom £0.25 a boxFolding Small Mailing BoxesFlat-packed, folds up in seconds, from 100 mmFrom £0.25 a box
Subscription Box MailersSame size every month, fresh print every quarterFrom £0.25 a box
Fragile Goods Mailer BoxesB-flute walls and a fitted insert for glass and jarsFrom £0.25 a box
Insert Fitted Mailer BoxesDie-cut board insert holds each item in placeFrom £0.25 a box
Literature MailersShallow and rigid for brochures, prints and samplesFrom £0.25 a box
Custom Printed Mailer BoxesFull colour outside, one colour inside or bothFrom £0.25 a box
Matt Black Mailer BoxesBlack board with white ink or one colour printFrom £0.25 a box
White Mailer BoxesWhite-lined board, printed or left plainFrom £0.25 a box
Brown Kraft Mailer BoxesPlain kraft, one or two colour print if you want itFrom £0.25 a box
Paper Padded MailersPaper cushioning inside, peel and seal stripFrom £0.25 a box
Compostable MailersSoft mailer for clothing and textiles, printed to orderFrom £0.25 a boxWhich board should your mailer boxes be made from?
Two board colours and two thicknesses cover nearly every job. The colour sets the look of the print; the thickness sets how the box handles in the post.
| Board | Thickness | Best for | Print notes |
|---|---|---|---|
| Brown kraft, E-flute | 1.5 mm | Clothing, stationery, cosmetics and most boxes under about 300 mm long | One or two colours sit crisply; add white underprint before full colour |
| White-lined, E-flute | 1.5 mm | Brands built on pale colours, photographs or fine type | Clean white face for full colour outside, inside or both |
| Brown kraft, B-flute | 3 mm | Larger boxes, jars, ceramics and dense, awkward items | Bold marks and simple line work suit the coarser surface |
| White-lined, B-flute | 3 mm | Bigger gift and subscription boxes that still need bright print | Full colour works well; set very small text a size larger |
E-flute is where most orders start because the walls stay slim and the corners fold tight. B-flute is worth its extra thickness on boxes over about 300 mm and on contents that push against the walls. We set out the trade-offs in our E-flute and B-flute board comparison.
Design Your Mailer Box
Pick a box, upload your logo and see it placed on a real photo of that mailer. When you like the look, send it over with your size and we turn it into a proper print proof.
Your logo is placed on a real photo of our box. A designer redraws it to scale on the dieline and sends a free proof before anything is printed.
How does ordering a mailer box work?
Four stages take you from a first message to flat bundles at your door.
Quote
Send the inside size, board, print and quantity. A custom quote comes back within one working day, starting from £0.25 a box.
Proof
We place your artwork on the flat net of your box and email a free proof. Nothing goes to print until you say yes.
Production
Your boxes are printed, die-cut and creased over 4 to 6 working days once the proof is approved.
Delivery
Free tracked delivery to UK mainland addresses in 2 to 3 working days, packed flat and strapped in bundles.
Who orders mailer boxes from us?
Mostly small UK sellers who pack orders themselves. Some post a dozen parcels a week from a spare room; others run a stockroom with a packing bench and a printer for labels.
What they share is a product that deserves better than a plastic bag, and a postal band they would rather not go over. We size the box around both.
- Clothing and accessory brands sending folded garments with a card
- Candle, skincare and soap makers posting jars and bottles in fitted inserts
- Subscription box businesses repeating one size every month
- Print sellers and illustrators who need artwork to arrive flat
- Gift and craft shops building bundles for birthdays and Mother's Day
Why post in a box rather than a bag?
A courier bag folds around whatever is inside it. A mailer box gives the product four walls, a floor and a lid, so corners stay sharp and soft goods arrive folded the way you packed them.
It also changes the first few seconds at the door. The customer lifts a lid instead of tearing a seam, and the inside of that lid is a panel you can print.
How do postal bands shape your mailer box size?
Royal Mail prices parcels by size band, so a few millimetres can move a box into a dearer band. Large Letter allows 353 x 250 x 25 mm outside, Small Parcel 450 x 350 x 160 mm and Medium Parcel 610 x 460 x 460 mm.
Tell us the band you want to post in and we work backwards from its limit, taking the board thickness off each side. Our guide to mailer box sizes and Royal Mail bands shows which inside sizes land where.
Do your products need an insert or void fill?
Soft goods rarely do. A folded jumper or a wrapped bar of soap sits happily in a box sized with the right clearance.
Glass, ceramics and sets that must arrive in order are different. A die-cut board insert gives each item its own opening, dividers split the box into bays, and paper void fill takes up spare depth. All three are quoted with the box, and we cover the options in our guide to inserts for fragile goods.
What do custom mailer boxes cost?
Prices start from £0.25 a box, and every order gets its own custom quote. Size, board, print coverage and quantity all move the figure, so we price the job you describe rather than a list.
Minimums are low and set per job. Send your three measurements and a rough quantity through the mailer box quote request form, and add a logo if you have one ready.
Common mailer box sizes and the band each one posts in
These inside sizes are starting points that suit common products. Every box is cut to your own measurements, so treat the chart as a guide rather than a stock list.
| Inside size (L x W x H) | What it holds | Postal band |
|---|---|---|
| 160 x 110 x 20 mm | Earrings on a card, a lip balm pair or a set of badges | Large Letter |
| 220 x 160 x 20 mm | A5 notebook, greeting cards or a pair of socks | Large Letter |
| 320 x 230 x 20 mm | A4 prints, brochures and certificates laid flat | Large Letter |
| 200 x 150 x 50 mm | A candle jar, a serum and cleanser, or a mug | Small Parcel |
| 250 x 180 x 80 mm | Two folded T-shirts or a three-piece skincare set | Small Parcel |
| 300 x 220 x 100 mm | A hoodie, a boxed homeware gift or a hamper for one | Small Parcel |
| 350 x 250 x 120 mm | A pair of trainers or a subscription box with several items | Small Parcel |
Measure inside, check outside
The size we quote is the inside: the space your product sits in. Measure the item at its longest, widest and tallest points and add 3 to 5 mm a side so the lid closes without bowing.
Postal bands measure the outside, which is the inside plus the board on each face. E-flute adds about 3 mm to each measurement, so a box that is tight to a band limit inside will not fit it outside. Check the current band limits before you order.
Full size chart and postal bandsGuides for getting the box right
Short, practical reads on measuring, board, inside print and inserts, written for people who pack their own orders.
Mailer Box Sizes and Royal Mail BandsWhich inside sizes land in Large Letter, Small Parcel and Medium Parcel, and how to stay in the cheaper band.
E-Flute vs B-Flute: Which Board for Your Mailer BoxHow the two corrugated grades differ in thickness, print, fold and protection, and which to pick.
Printing Inside the Lid of a Mailer BoxWhat inside print can do, how it is set up on the dieline and what it adds to the job.
Mailer Box Inserts for Fragile GoodsDie-cut board inserts, dividers and void fill for glass, jars and ceramics sent by post.
How to Measure a Mailer BoxInside size, clearance and board thickness, and how to send a size we can quote.Questions before you order
What is a mailer box?
A mailer box is a corrugated box cut and creased from one flat sheet, with a hinged lid that folds over and locks into the base. It needs no glue and usually no tape, and it is strong enough to post as it is.
How are custom mailer boxes different from stock boxes?
A stock box comes in fixed sizes and plain board. A custom mailer box is cut to your inside measurements and can carry your print outside, inside or both, so the product fits without padding and the parcel carries your brand.
How much do mailer boxes cost in the UK?
Our mailer boxes start from £0.25 a box. The real figure depends on size, board, print and quantity, so every order is priced in a custom quote within one working day.
Which mailer box style should I start with if I am unsure?
Start with a tuck top: it suits most products and closes without tape. Ear lock feels firmer; side loading suits flat items like prints.
Can custom mailer boxes be printed inside the lid?
Yes. The inside of the lid and base can be printed in one colour, two colours or full colour, on the same sheet as the outside.
Can a mailer box fit through a letterbox?
A slim one can. To post as a Royal Mail Large Letter the outside must stay within 353 x 250 x 25 mm, which in E-flute board means an inside depth of about 20 mm.
Do mailer boxes need tape to close?
Most of our styles lock shut with a tuck or with side ears, so tape is optional. A printed sticker over the front edge is a popular seal that also shows whether the box has been opened.
Should I choose kraft or white mailer boxes?
Brown kraft gives a natural, handmade look and suits one or two colour print. White-lined board shows pale colours and photographs more brightly, so it suits brands whose artwork relies on exact tones.
How long does a whole mailer box order take from first message?
Allow one working day for the quote, the time you take to approve the proof, 4 to 6 working days for production, then 2 to 3 working days for delivery.
Can I order mailer boxes before my logo is finished?
Yes. You can order plain boxes now, or ask for a quote and send artwork later. Nothing is printed until a proof has been approved, so there is no rush to have files ready on day one.
Do you make padded mailers as well as boxes?
Yes. Alongside the corrugated boxes we make paper padded mailers and compostable mailers for soft or slim items that do not need a rigid box.
Can one order include mailer boxes in two different sizes?
Yes. Many sellers order a small and a large size together to cover most of their range. Each size gets its own line on the quote and its own proof.
Your question is not here? Ask on WhatsApp or call +44 7578 382054.
Not sure which mailer? Tell us what you post
Send the product, a rough inside size and a quantity. We reply with a custom quote within one working day with a price and a free design proof. Prefer to talk? Call +44 7578 382054 or message us on WhatsApp.