Have a question about the Slotbox®?

Check out the FAQ and if you don’t find what you are looking for, please contact the Slotbox.

We are happy to help.   

  • The Slotbox came to be in 2016. It was developed by the Canadian glass artist Sarah Mulligan when she could not find a box to fit Canada Post lettermail.

    It is the original foldable box mailer developed specifically to send in Canada Post lettermail.

    A proudly a 100% Canadian product made in British Columbia and business operating in Victoria, BC.

    All 5 sizes of the SLOTBOX product are made of shipping grade e-flute cardboard.

    Choosing the Slotbox for your business supports Canadians just like you!

    Thank you :)

  • Having a lettermail slot template is a great tool to confirm you pass the 20mm slot prior to the trip to the post office.  You can buy one here on the Slotbox website or visit the RESOURCE page for more options.

  • A requirement for Canada Post machinable mail is the box is to be enclosed in an envelope - for ease of box into / protect the mail processing machinery.

    This being said, Canada Post has been known to accept a box not in an envelope if it meets all the size requirements and is taped securely closed. Mailing the box without an envelope is entirely at the discretion of Canada Post.

    If you wish to mail without an envelope, have a CP associate accept it into their system.

    The Slotbox always recommends the use an envelope. This way you can skip the post office line-up and drop off in a street receptacle and your customer will have a nice little gift box to reuse!

  • You can mail the box at your local post office or in the large red street receptacles. 

    Box mailers can not be mailed at the Canada Post community hubs outgoing mail receptacles. …I agree, it’s super frustrating!

    These hubs have been designed by Canada Post with a slanted red metal rain guard to impede oversize lettermail. It is intentional. It would fill up too fast with large mail, and is only intended for standard mail.

    It is not the box, it is Canada Post.

    Know that the “20mm” size requirement of lettermail is for the processing of mail in machinery at the CP facilities, not the receptacle where you drop mail off.

  • A folded box that is properly folded and taped shut is 18.5 mm and easily has wiggle room for the thickness of an envelope.

    Slide the box through a 20mm template before packing it to ensure it was folded correctly. Then pack the box.

    if you find the box getting stuck on the corner going through the slot template, gently tamp edge down with hammer

    If you find the box getting stuck in the middle going through the slot template, try removing some of your packing material and/or rearrange your items.( ie: take stud earrings off the card hanger, use less tissue paper etc… ) -  to minimize bulging and try again.

    The Slotbox works for 1000’s of Canadians, but if can not do miracles! If your product is too big it will have to be sent as a parcel service.

  • Sorry, customization of the Slotbox is not an offered service.

    stamping your own logo is very easy thing to do yourself, at a fraction of the cost of a print service. There are many Canadian companies that will create a custom rubber stamp for you. Apply ink and stamp your box before folding to ensure a nice crisp image. You will find a few companies listed in the RESOURCE section of the website.

  • YES OF COURSE! A custom listing catered to your box needs is welcomed. Email info@theslotbox.com with your request and don't forget to provide your address for an accurate shipping quote.

  • YES, we are located in Victoria BC. The Slotbox is located at 2524 Bridge Street ( corner of John St) as part of “Sarah Mulligan Glass Designs” Hours vary weekly, please confirm hours before stopping by: call/text 250 884-0189.

  • YES. In the checkout after you enter your email address the option for local pick will be given. Choose PICKUP and the website will bypass the shipping fees. PLEASE NOTE: express wallet GOOGEL PAY will skip the shipping choice step and you will not see the pick up option. Choose “More Payment options” below the G Pay button

  • YES!

    British Columbia PST exemptions are available for customers who provide the number directly to the order page when placed. Enter it in the "additional information" section. It is required to be on every invoice. It is not kept on file.

    The website will still collect the PST, but you will be refunded the appropriate amount. 

    Note: The Slotbox is not required to provide PST exemptions. If you forget to add your exemption #, you can apply to the Ministry for a refund for all your PST paid out on business expenses by mailing in a completed Application for Refund – General (FIN 355)

  • Yes. If you would like pay by e-transfer, please reach out to the Slotbox and it will be arranged.

  • Not as lettermail, but the Slotbox is still a sturdy little mailing box, so as boxes go, you can certainly use it to safely send small items.

    Anything leaving Canada that is not a paper document no longer qualifies for lettermail rates and is sent as a parcel service with a customs declaration.

  • YES! You are welcome to purchase your own shipping label to forward to the Slotbox. A custom listing is required to bypass the shipping fees.

    Email your order request (include box size, quantity and colour) and a listing will be prepared for you.

    You will receive and email with the weight and dimensions and Slotbox ship address for you to create ship label; you email the Slotbox the label.

    Please note, the SLOTBOX will not take parcels to depots. Pick up at

    Sarah Mulligan Glass / The Slotbox 2524 Bridge Street, Victoria BC. V8T5H3 .

    email: info@theslotbox.com

  • YES, PLEASE DO. Of course you can. The Slotbox is happy to answer any questions or inquiries you may have. Please send inquiry to info@theslotbox.com today.