To open a business in Singapore, the minimum requirements are:
Between 1 - 50 shareholders: A shareholder can either be an individual or a legal entity like a trust or another company. Singapore permits 100% foreign ownership of Singapore companies.
Paid-up capital: The minimum paid-up/share capital for a company to register in Singapore is S$1. Any time post incorporation, the share capital can be increased.
Company secretary: Every company must appoint a company secretary. This individual will help the directors to prepare and file all necessary documentation to keep the company compliant.
1 or more resident directors: At all time you will need at least one locally resident director. At the time of incorporation this is someone who is a Singapore citizen, Permanent Resident, or holder of an EntrePass visa.
A registered address in Singapore: The address that is provided for the company must be located in Singapore. It must be a physical address and a P.O. Box will not be accepted.
Other helpful things to keep in mind when registering a company
Your Business Activity Classification. At the time of incorporation every business in Singapore must select a SSIC code intended to describe their intended business activity.