Why a checkout rejects your address
Most online forms are built around a United States style address: a required ZIP code, a state dropdown, and a phone field that expects a fixed number of digits. Addresses in Hong Kong, Singapore, and Taiwan do not fit that shape, so the form refuses to submit or flags a field as invalid. The fix is almost never to change your address; it is to know what each country puts in those specific fields.
The postal code field
Hong Kong has no postal code. Leave the field blank, or enter 999077, a widely used placeholder that is not an official code. Singapore uses a real 6-digit postal code that maps almost to a single building, so enter it exactly. Taiwan uses a 3+3 code: a 3-digit district code is enough for most forms, and the full 6-digit code speeds up sorting. See what 999077 means.
The state or province field
None of the three has a US-style state, so a required dropdown is the second thing that traps people. In Hong Kong, enter your region: Hong Kong Island, Kowloon, or the New Territories. In Taiwan, enter your city or county, such as Taipei City. In Singapore, there is no province at all; enter Singapore or leave it blank.
The phone field
Use the country calling code so an international courier can reach you: +852 for Hong Kong (8 digits), +65 for Singapore (8 digits), and +886 for Taiwan, dropping the leading zero of the local number.
Common form errors
- Inventing a postal code for Hong Kong. Use 999077 or leave it blank; a random number can misroute the parcel.
- Leaving the state field on its default. A wrong default can send the order to the wrong region; set it to your region, city, or Singapore.
- Writing the phone number without the country code. An overseas courier needs +852, +65, or +886 to call you.
- Putting the building in the street field. Keep the flat, floor, and building separate from the street line so the address stays readable.
The guidance here is general and applies to any shop or courier form; it is not tied to one platform, so nothing about a specific site is assumed.