Comprehensive Guide to SIM Exchange/Return at C.T.S Corporation
Complete step-by-step instructions for safely exchanging or returning your SIM card or Pocket Wi-Fi device to C.T.S 株式会社 using Japan Post Letter Pack 370 / 430.
Official Return Guide Diagram
Please review the official visual tutorial below to ensure all recipient fields and return items are completed properly:
Step-by-Step Return Procedure
Purchase Letter Pack Envelope (レターパックライト)
Visit any nearby convenience store (Lawson, FamilyMart, 7-Eleven) or Japan Post office and ask to purchase a blue Envelope 370 / 430 (レターパックライト 370円 / 430円).
Fill in the "TO" (お届け先) Recipient Section
Fill in the recipient information in the お届け先 (TO) block exactly as shown in the example diagram:
Fill in the "FROM" (ご依頼主) Sender Section
Fill in your personal sender information in the ご依頼主 (FROM) section: your full name, postal code, Japanese home address, and contact phone number.
Pack Equipment Securely Inside Envelope
Carefully place the SIM card (or Pocket Wi-Fi device + original charging cable) inside the Letter Pack envelope and seal the adhesive flap firmly.
Take a Photo & Send to C.T.S Page
Take a clear photo of the filled envelope showing the recipient address and tracking sticker. Send the picture to our official customer care page (WhatsApp, Facebook Messenger) so our admin team can record your exchange/return request.
Peel Off the Tracking Sticker (はがして差出し)
Tear off and retain the tracking barcode sticker labeled 「ご依頼主様保管用シール」(はがして差出し). Keep this sticker safe to track your package delivery online.
Drop Envelope into Nearest Post Mailbox
Finally, drop the sealed envelope into any red Japan Post mailbox on the street or at convenience stores. Your package will be collected and delivered directly to our processing warehouse.
- Rented via a specific agent/page: Please write: "Page Name + Sender's Full Name" in the sender section so our team can immediately identify your customer account.
- Pocket Wi-Fi returns: Ensure the device is in clean, good operating condition and always include the charger and charging cable to prevent missing equipment deductions.
Frequently Asked Questions
Why does Letter Pack state 370 on older guides vs 430 today? +
How long does it take to receive an exchange SIM card? +
Can I return the package directly at the post office counter? +
Have Questions About Your SIM Exchange or Return?
Our multilingual customer care team is available to assist you in English, Vietnamese, and Japanese.
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