Need help with SUMO DAY?

For pre-purchase, access, or product questions, email support@sumoday.guide. For ordinary product and access support, we usually reply within two business days, Monday to Friday excluding Japanese public holidays.

Contact

Email support@sumoday.guide. Requests for the supplier's legal name, business address, and telephone number are not subject to the general two-business-day target: we answer them without delay, in time for review before purchase. Use the subject “Seller information request” and do not order until you receive the reply.

Third-party bookings

For a booking made after leaving SUMO DAY through a clearly labelled partner link, contact the named provider shown on its confirmation. That provider—not SUMO DAY—controls the price, availability, payment, change, cancellation, refund, and booking support.

What to include

Please include your Lemon Squeezy order number, the email used for purchase, your device and browser, and a short description or screenshot of the problem.

Keep private information safe

Never send full payment-card details or publish your license key. SUMO DAY will never ask for your complete card number.

Payments and receipts

For payment, receipt, or charge questions, use the support options in your Lemon Squeezy receipt. For guide access and content questions, contact SUMO DAY.

Last reviewed: 26 August 2026