{"id":33118,"date":"2026-09-20T10:49:59","date_gmt":"2026-09-20T08:49:59","guid":{"rendered":"https:\/\/wifi.se\/en\/blog\/faq\/what-is-a-sim-card\/"},"modified":"2026-09-20T10:49:59","modified_gmt":"2026-09-20T08:49:59","slug":"what-is-a-sim-card","status":"publish","type":"faq","link":"https:\/\/wifi.se\/en\/blog\/faq\/what-is-a-sim-card\/","title":{"rendered":"What is a SIM card?"},"content":{"rendered":"

A SIM card<\/strong> identifies your mobile data service on the mobile network. When the SIM card is in a compatible router, phone or tablet, the device can register on the mobile network.<\/p>\n

The SIM card is not the internet connection itself. For the internet to work, the service must be active, there must be a data package, the device must have reception and the right network settings must be enabled.<\/p>\n

\n

With SIM problems<\/h3>\n

It is best to switch off the router before taking out or inserting the SIM card. Check that the card is the right way round and fully inserted. After changing the SIM, the router should be restarted so that the modem registers on the mobile network again.<\/p>\n

Check the SIM card systematically<\/h3>\n

With problems with a physical SIM card, it helps to separate the card from the router. If possible, test the SIM card in a phone with mobile data and roaming switched on and Wi-Fi switched off. If the internet works there, you know that the SIM card and the service basically work.<\/p>\n

If it still does not work<\/h3>\n

Check the status of the service and then test one thing at a time. When you contact Wifi.se support, please tell us which router you are using, which SIM\/eSIM it concerns, which country you are in and what you have already tested. That way we can start directly with the right troubleshooting step.<\/p>\n<\/div>\n

Useful links<\/h3>\n

\u2192 See SIM cards for Sweden and Europe<\/strong><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"template":"","meta":{"_acf_changed":false},"faq_category":[505],"class_list":["post-33118","faq","type-faq","status-publish","hentry","faq_category-physical-sim"],"acf":[],"yoast_head":"\nWhat is a SIM card? | Wifi.se<\/title>\n<meta name=\"description\" content=\"A SIM card identifies your mobile data service on the mobile network. 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