Telephone country codes never begin with zero.
Country code +38, dialed as 00 38 from many places, is an incomplete code for somewhere in Europe. You need one more digit to specify the country. (+38 was formerly the code for Yugoslavia, but there are now several codes in the range +380 through +389, including the former Yugoslav republics and other countries.)
Country code +8, dialed as 003 8 from many places, is an incomplete code in eastern Asia, or a transnational telephone service. You need at least one or two more digits to specify the country or service.
To avoid confusion, it is best to write an international telephone number in correct international format, beginning with the plus symbol and the correct telephone country code (e.g., +389 or +886), omitting any dialing prefix.
(The plus signmeans "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)
Leichtenstein is telephone country code +423.
where is telephone country code 1816
That is not a country code.
ZIP Codes are postal codes only for use in the United States, and they always have 5 digits.0038 is the way that telephone country code +38 is presented in many parts of the world, but +38 is an incomplete code. You need one more digit. (The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, and many other countries use different prefixes.)0038 may be a valid postal code in a number of different countries, but a postal code generally specifies a town or a part of a city, not an entire country.
Country code +57 is Colombia.
Country code 52 is Mexico.
Fiji has telephone country code +679.
Gibraltar is country code +350.
Moldova is country code +373.
Slovenia is country code +386.
Vanuatu is country code +678.
Niue is country code +683.