Questions about your order, installation or a refund? Email us. We reply in English, Dutch or German, day and night.
Send your question to support@holysim.nl. We reply in English, Dutch or German, 24 hours a day, 7 days a week. All support runs by email, so you always have an answer you can read back later.
Already ordered? Include your order number (HS-...), your destination and the device you use the eSIM on. That lets us look up your order right away and help you specifically.
Last updated: 4 September 2026.
Is your eSIM not working yet? First check that data roaming is on and that the eSIM line is enabled for mobile data. Our guides contain step-by-step instructions per device, and the FAQ page answers the most common installation questions.
Still stuck? Email us with a short description of what you see, such as an error message or no signal. A screenshot of your eSIM settings helps us reply faster.
No email with your eSIM? Check your spam folder first and verify the email address you entered when ordering. After a successful payment we send your eSIM with QR code by email straight away.
As long as your eSIM has not been delivered, you can cancel your order free of charge via support@holysim.nl. What is possible after delivery is described in our refund policy.
HolySim is a trading name of Electrorent B.V., registered at Schipholweg 103, 2316 XC Leiden, the Netherlands.
Registered with the Dutch Chamber of Commerce under number 99573970. VAT ID: NL869045519B01. HolySim has no shop or front desk; all customer contact runs by email.
Questions about our partner programme, a collaboration or a press request also go to support@holysim.nl. Put the topic in the subject line so your message reaches the right person.