How to Return a SIM Card or Pocket Wi-Fi After Cancelling Your Subscription
Complete guide for customers returning rented SIM cards or Pocket Wi-Fi devices to C.T.S 株式会社 via Japan Post Letter Pack.
Prepare the Device & Accessories
Carefully check that the SIM card or Pocket Wi-Fi device is ready to be returned. If you are returning a Pocket Wi-Fi or Home Router, ensure the original charging cable and power adapter are packed together.
Purchase a Letter Pack (レターパック)
Purchase a Letter Pack Light (Blue) or Letter Pack Plus (Red) from any nearby post office or convenience store (such as Lawson, FamilyMart, or 7-Eleven).
Fill in the "TO" (お届け先) Destination Section
Carefully write the official C.T.S receiving warehouse details in the お届け先 (TO) block:
Fill in the "FROM" (ご依頼主) Sender Section
In the ご依頼主 (FROM) box, clearly write your own details: your full name, Japanese address, postal code, and phone number as registered on your account.
Insert Device & Peel Off Tracking Sticker
Place the SIM card or device securely inside the Letter Pack envelope and seal the flap tightly.
Take a Photo & Send to C.T.S Admin
Take a clear photo of the sealed Letter Pack showing both the filled addresses and the tracking sticker. Send this photo to C.T.S customer support via WhatsApp or Messenger so our admin team can record your return notice.
Drop Into Nearest Post Mailbox
Simply drop the sealed Letter Pack into any red Japan Post mailbox on the street or inside convenience stores. No queuing at post office counters is needed!
Frequently Asked Questions
Which Letter Pack should I purchase: Blue or Red? +
What is the deadline for returning the device after cancellation? +
How will I know when C.T.S has received my return? +
Need Assistance with Your Return?
Our multilingual customer care team is available to assist you in English, Vietnamese, and Japanese.
↑ Back to top