I believe there are VOIP phones that are sim card based. Imagine a country that doesn't have land lines but folks want a home phone.

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wolrah 2 hours ago | parent [-]

There are SIP to cellular gateways which have historically been very popular in regions where landline to mobile calls cost money but mobile to mobile do not, but they mostly don't exist in the US market other than high-density devices mostly used by SMS spammers.

The only actual VoIP phone with a SIM card I'm aware of is the Yealink T74LTE which for a long time was exclusive to Verizon's business phone service but has recently become available for general purchase, those can support both SIM over LTE data and VoLTE (which is also basically SIP but over a prioritized channel).

	▲	Scoundreller an hour ago \| parent \| next [-]
		I'd like this kind of setup because my VoIP provider charges a couple bucks a month for 9-1-1 while sending 9-1-1 over cellular would be free
	▲	j45 14 minutes ago \| parent \| prev [-]
		I recall seeing some that were offered in Asia but might not be elsewhere. It looked like an office desk phone but instead of Ethernet, a SIM card goes only. Some came with a cordless handset with it too. seeing