As long as your mobile phone has international roaming, you will receive text messages, but the roaming number cannot be effectively used for personal health monitoring and follow-up care after you enter the country. Therefore, inbound passengers must apply for a Taiwan mobile phone number to facilitate the management and support care services provided by the civil affairs bureau and local borough chief. You should use a Taiwan mobile phone number to make a health declaration and receive an electronic health declaration receipt. If you do not have a Taiwan mobile phone number, you can make your declaration with your roaming number at the place of departure (an overseas station of the airline company). Once you arrive in Taiwan, you will need to purchase a SIM card of a Taiwan telecom service provider at the airport of arrival and install it before entering the country.