Do I need a visa to go to Thailand with a Hong Kong identity card?

This is necessary. You can't go to Thailand with your Hong Kong identity card. You need a Hong Kong Special Administrative Region passport. HKSAR passport holders can stay in Thailand for 30 days without a visa.

The main function of the visa:

Visa is a measure taken by a sovereign country to safeguard its sovereignty, dignity, security and interests. Visa is an important means for a sovereign country to implement entry and exit management. If citizens of one country want to go to other countries for visa samples, residence, business, study abroad, etc. He must have a valid passport or travel document, and another condition is to obtain a visa to other countries.

Under normal circumstances, a country issues visas to foreigners on the principle of equality and reciprocity between foreign countries and their nationals, and provides the same preferential treatment and convenience for the nationals of the two countries to interact with each other. However, there are also visa-free countries, such as 18 visa-free countries with China passports and 130 visa-free countries with American passports.

Generally speaking, foreigners are granted different entry visas according to the identity of the applicant and the purpose of entry, such as visas for traveling, visiting relatives, emigrating, studying abroad and working, and the residence time after entry is limited. Due to the different types of visas, the relevant materials needed are also different.

Generally, short-term residence applications have fewer restrictions and shorter waiting time for approval. For the purpose of long-term residence, the application is more restricted and the waiting time is longer. A country has no obligation to allow foreigners to enter the country unconditionally (unless there is a treaty), and a foreigner has no right to ask a government to allow him to enter the country.

A sovereign country always has restrictions on the entry of foreigners. With the development of international trade, international political relations and the prosperity of tourism, visa regulations in many countries tend to be simplified. There are also agreements between countries to exempt visas or simplify visa procedures.