CANADA POST LETTERMAIL EXPLAINED

CANADA POST LETTERMAIL EXPLAINED

Lettermail can be sent all over the world for as little as a stamp, but what can and can’t be sent and where may get a little confusing. In a nutshell, if your mail is leaving Canada, then only paper can be mailed as lettermail. Non-paper documents must be sent as a parcel with a customs declaration of contents. Good news, as long as your lettermail stays within Canada, you can send items that are not paper documents.


Canadian Lettermail falls into 3 categories,

*Standard lettermail (paper only* Worldwide)

*Oversize Lettermail (paper only* Worldwide)

*OTHER (Non-standard / Oversize Lettermail) (Canada Only)

* NO TRACKING with any LETTERMAIL service*

(Registered Mail is an add-on option if you wish to have tracking, $100 insurance, and proof of delivery with a signature.) .


1) “Standard Lettermail” is your classic thin envelope, like a utility bill, invoice, or birthday card that arrives in your mailbox. It is required to be under 5mm thick, under 30-50grams and be only PAPER only*.  You can mail this anywhere in the world. Postage based on weight and destination.

2) “Oversize Lettermail” This is very similar to standard lettermail but is for bigger thicker mail like documents and legal forms. It requires to be under 20mm thick and under 500g.  Size is required not to exceed 380mm (L) x 270mm (W) x 20mm (D),  and be only PAPER only*. You can mail this anywhere in the world, and postage varies based on weight and destination.

3) OTHER “NON-STANDARD / OVERSIZE LETTERMAIL”  is the service that the SLOTBOX was designed for - It allows Canadians to mail NON-PAPER items** like jewelry, soap, enamel pins, guitar strings, Lego, etc… as Lettermail but WITHIN CANADA ONLY.  Postage is based on weight increments up to 500g.     

Size Requirements

Minimum: L 140mm   W 90mm  D 18mm    3g  

Maximum:  L 380mm  W 270mm    D 20mm   500g       

Postage based on weight: as of May 6, 2024

3g - 100g     $2.09  (There is a stamp for this value)

100g - 200g   $3.43   (You have to get creative with stamps or go to post office when over 100g)

200g - 300g  $4.78  

300g - 400g  $5.48

400g - 500g  $5.89

over 500g  = parcel rates  

All information on the Slotobx website is for reference purpose only.

Please visit the Canada Post website for all official and current requirements and regulations.

*There are a few exceptions to the paper only rule. ie: flexible magnets (think business card for fridge), coin - not loose, dry biological specimen. Please visit Canada Post website for all details.

sarah mulligan