Last Updated on March 29, 2022
Note: This page will be updated in the future with more shipping services.
Japan Post
Name of Service | Size | Thickness Limit | Weight Limit | Price | Other Notes |
---|---|---|---|---|---|
Smart Letter スマートレター | 250mm x 170mm (B5) | 2cm | 1kg | ¥180 | ・Same shipping speed as normal mail ・Only delivers on weekdays ・No tracking service |
Letter Pack Light レターパックライト | 340mm x 248mm (A4) | 3cm | 4kg | ¥370 | ・Faster shipping speed than normal mail ・Delivers on weekends ・Has tracking service |
Letter Pack Plus レターパックプラス | 340mm x 248mm (A4) | No limit | 4kg | ¥520 | ・Faster shipping speed than normal mail ・Delivers on weekends ・Has tracking service |
Smart Letter (スマートレター)


Size: 250mm x 170mm (B5)
Thickness limit: 2cm
Weight limit: 1kg
Price: ¥180
Smart Letter envelopes are good for sending small and thin items.
These can be purchased at your local post office or at some convenience stores. The flat-rate price includes the cost of the Smart Letter envelope and shipping. These envelopes are delivered to mailboxes. Unlike Letter Pack Light and Plus envelopes, this type does not offer a tracking service.
The blue border of the envelope is 1cm thick, so you can fold it along this border to make the envelope 2cm wide.
Letter Pack Light (レターパックライト)


Size: 340mm x 248mm (A4)
Thickness limit: 3cm
Weight limit: 4kg
Price: ¥370
Letter Pack Light envelopes are good for sending thin items. These can be purchased at your local post office or at some convenience stores. The flat-rate price includes the cost of the Letter Pack Light envelope, shipping, and a tracking service. These envelopes are delivered to mailboxes, whereas Letter Pack Plus envelopes are delivered face-to-face to the recipient. You can track the envelope by accessing this page and entering the 12-digit tracking number located on the “sender to retain” sticker.
How to ship
- Purchase a Letter Pack Light envelope
- Write the addresses
- Keep the “sender to retain” sticker (ご依頼主様保管用シール)
- Drop off the envelope to your local post office or post box
Letter Pack Plus (レターパックプラス)


② Do not remove the delivery certificate sticker
Size: 340mm x 248mm (A4)
Thickness limit: no limit
Weight limit: 4kg
Price: ¥520
Letter Pack Plus envelopes are good for sending items that have a thickness of more than 3cm.
These can be purchased at your local post office or at some convenience stores. The flat-rate price includes the cost of the Letter Pack Plus envelope, shipping, and a tracking service. These are delivered face-to-face to the recipient, whereas Letter Pack Light envelopes are delivered to mailboxes. You can track the envelope by accessing this page and entering the 12-digit tracking number located on the “sender to retain” sticker.
How to ship
- Purchase a Letter Pack Plus envelope
- Write the addresses
- Keep the “sender to retain” sticker (ご依頼主様保管用シール)
- Drop off the envelope to your local post office or post box

The great thing about the Letter Pack Plus is that you can change the shape of it from an envelope into a box.
Watch this tutorial on how to do this.
Note: Due to a price increase from ¥510 to ¥520, the Letter Pack Plus envelope shown in this video looks different from envelopes available now.
Things to keep in mind:
The dotted lines on the back of the envelope must be completely covered when you seal it.
The delivery certificate sticker (配達証) must not be peeled off. Letter Pack Plus envelopes with this sticker peeled off cannot be used.