Hey Kona213, thank you for finding the unobstructed time out of your bustling day to ask us your question about the Samsung Galaxy S24 Ultra. The advertised unlocked Galaxy S24 Ultra is compatible with T-Mobile, AT&T, Boost Mobile, Cricket, H2O Wireless, MetroPCS, Mint Mobile, Simple Mobile, Sprint, Ultra Mobile, US Cellular, and Verizon. It is not necessary to purchase an unlocked device, however, some customers prefer to have the unlocked option available to purchase so that they may choose their carriers and not have their device locked to one specific carrier's network. Hope that helps answer your question! Feel free to reach out to Samsung Support if you would like any further assistance. Thank you for being a trustworthy Samsung customer. - Debra