Introduction

The TCG section on Chinese visa explains the general principles of what entry visas are.  Although Hong Kong and Macau are parts of the People's Republic of China (PRC), as Special Administrative Regions (SAR), each has its own entry regulations.  This also means that you might need a visa to the HKSAR from the Chinese mainland and one to enter the Chinese mainland from Hong Kong – so if you are on the mainland and want to visit Hong Kong and return, you must have a valid entry Chinese visa or obtain a new one in Hong Kong (and although it is normally granted, it is not a 100% certainty).  

Always remember that each country (and Chinese SARs) has the right to refuse entry to any person, whatever the regulations permit, and that even when you have a visa you can be denied entry at the border.   Also, the information provided here is for people travelling on standard passports, not special ones like diplomatic or service passports, nor special or restricted passports.

Generally, Hong Kong is very open to foreigners who simply want to visit as a tourist to conduct business activities for an overseas business such as visiting clients and prospects, providing training, or attending trade fairs.  Overall, the rules are essentially the same as under the British administration that preceded the SARs return to Chinese control.

There are special rules applying to residents of the Chinese mainland, those living in Taiwan, for Macauans visiting HK.  These are described at the end of this article.

There is full information on the HK Immigration Department webpage http://www.immd.gov.hk/en/services/hk-visas/immigration-entry-guideline.html. In particular, you can get all the forms and the guidelines from http://www.immd.gov.hk/en/forms/hk-visas.html. If you still need clarification on any point and you should contact a Chinese consulate, or in Hong Kong, contact the HK Immigration Department, or on the Mainland, from the Beijing Office of the Government of the HK SAR, whose official webpage is www.bjo.gov.hk/en/home/index.html.

Basic criteria for all foreign visitors
The following are the official minimum requirements for foreign visitors to HK. 
• have a minimum validity on your passport of 1 month beyond the intended stay (or the duration of the visa may be restricted so that there will be one month after the visa expiry)
• properly complete the immigration card on arrival
• have a visa if your nationality is required to have one
• have onward or return travel arrangements
• have sufficient funds for your stay without working (based on Immigration's definition, not yours)
• not have a serious criminal record or be likely to be involved in crime, nor be considered a security risk

Most travellers, especially from western countries, are not checked for compliance with the last three but all travellers should allow for the possibility that immigration might choose to check you.  You should also check with your airline's regulations as they may not allow you to fly if you do not meet stated entry requirements.  

Entry as a tourist without a visa
Most tourists do not require a visa for a visit to HK, please see the Non-Visa to Hong Kong for Foreign Countries/Areas. All arriving visitors at Immigration control points will be issued with landing slips in lieu of stamping on their passports/travel documents. Conditions and limit of stay in HK, as well as visitor's personal information and arrival date will be included in the landing slip. Upon departure, no slip will be issued and the travel documents will not be stamped. 

It is not possible to list the requirements country by country, but you can check out your situation at the HK Immigration Department information at http://www.immd.gov.hk/en/services/hk-visas/visit-transit/visit-visa-entry-permit.html

In summary, the most favoured are British nationals who, provided they meet the basic criteria, may enter HK for 180 days without obtaining a visa in advance.  Canadian, Australian, New Zealand most European nationals may enter for 90 days.  Others are variously restricted to 90, 30, or 14, or 7 days, or in the case of a few countries will only be permitted to enter having previously obtained a visa.  Most tourists can easily take the ferry from HK to Macau which has a policy similar to Hong Kong's and typically you will not normally require a Macau visa. You can exit Hong Kong and re-enter for another stay.  There is usually no problem re-entering unless the immigration authorities feel you are breaking some other rules such as being engaged in business.  However, you may be allowed to visit for a longer duration by applying for a visa prior to travel – but it is at the discretion of the consular office whether to grant it or not. 

Visitors are not normally permitted to change the type issued (or move from a non-visa situation to obtaining one) after arrival but of course it is easy to exit HK and apply for a Hong Kong Visa again.