Czech Republic   / T-Mobile

eSIMno offers 24/7 support via WhatsApp and email. Our human support team - not bots - handles installation help, troubleshooting, billing questions, and refund inquiries. Most issues are resolved within minutes during business hours and within a few hours overnight.

Yes - you can install it immediately after purchase. Your order email arrives within minutes and contains the QR code, a one-tap install link and the manual codes, plus an "Install eSIM" button; you can also sign in > My eSIMs > Install any time. Installing right away does not start your plan - the validity countdown only begins when the eSIM connects to a mobile network inside your plan's coverage area. Keep the eSIM line and Data Roaming off until you are ready to start; if your plan covers the country you are in right now, turning the line on starts the countdown immediately.

Yes - setting it up before your trip is the easiest approach. Your confirmation email contains the QR code, a one-tap install link and the manual SM-DP+ / activation codes (the same options are also available via sign in > Profile > My eSIMs > Install). While on Wi-Fi at home, install it with the one-tap link on your phone, or - to use the QR - show it on another screen or a printout and scan it with the phone you are setting up (not another phone). Installing does not start your plan: the validity countdown only begins when the eSIM connects to a mobile network inside your plan's coverage area. Keep the eSIM line and its Data Roaming off until you are ready to start - if your plan covers the country you are in right now, turning the line on connects and starts the countdown immediately, even if you do not browse anything. Please note: once installed, an eSIM is considered used and is no longer eligible for a refund.

You can't really lose it - your QR code is in your order confirmation email, and also in the install pop-up on the website. To reopen it any time before activation, tap "Install eSIM" in your order email, or sign in at esimno.com and go to Profile > My eSIMs > Install. Both show the QR code together with the one-tap install link and the manual SM-DP+ / activation code. Note the install codes are one-time-use: once the eSIM is installed on a device they can't be reused - reopen the installer (My eSIMs > Install) to display a fresh QR if you need one.

Your eSIM keeps its validity period running whether you're using it or not - pausing your trip doesn't pause the timer. If you return home, the eSIM stays dormant on your device until you travel again or it expires. You can disable it in cellular settings to avoid accidental usage.

We recommend turning off cellular data and data roaming on your original SIM while abroad to avoid accidental roaming charges. You don't need to physically remove the SIM - just disable data and set the eSIM as your primary data line.

Yes - if your home SIM stays installed and active, calls and SMS to your home number arrive normally. The eSIM only handles data; voice service stays on your home line. Just remember that incoming calls and texts to your home number while abroad may trigger roaming charges from your home carrier.

Yes. Your WhatsApp number stays linked to your home SIM, so all your chats, contacts, and groups remain unchanged. WhatsApp uses data (not the SIM line directly) for messages and calls, so it works seamlessly over your eSIMno data.

A Wi-Fi connection is required to install your eSIM, so we recommend setting it up before you leave home. Activation can happen later, either right before departure or after you land at your destination - but the initial QR scan needs Wi-Fi.

eSIMno partners directly with local operators in over 200 countries, eliminating intermediaries. This direct relationship lets us offer competitive pricing, extensive coverage, and faster activation than resellers who route data through third parties.

eSIMs use ground-based cellular networks, so they don't work in flight or at sea outside coastal coverage. They activate as soon as you connect to a partner network on land. For in-flight or maritime data, you'll need the airline or ship's onboard Wi-Fi.

Coverage depends on the partner network's reach in Czech-republic. Major cities, tourist areas, and highways typically have strong 4G/5G coverage. Remote rural areas may have weaker signal or fall back to 3G. Download offline maps before heading off the beaten path.