Mobile phone service providers supply access to cellular networks for making calls, sending texts and using mobile data. They may operate their own network infrastructure or sell services using another operator's network. Customers can usually choose between pay-monthly contracts, SIM-only plans and pay-as-you-go arrangements, with options that vary in data allowances, call and text inclusions, contract length and eligibility requirements. Providers may offer physical SIM cards and eSIMs for compatible devices. Services can include domestic and international calling, roaming, voicemail, number transfer and account management through online portals or apps. Some providers also offer mobile broadband, data-only SIMs, family or shared-data plans, and packages designed for business use, such as multiple connections or centralised account administration. Customer support may cover billing queries, plan changes, usage information, network availability and help with service faults.