In Estonia you don't need to declare anything with a company if you don't distribute profits, with exceptions to non-cooperative jurisdictions.
You declare profit distributions and taxes paid abroad when you need to access tax credits or participation exemption.
Even for individuals there exists a tax deferral regime under which you don't declare untaxed dividend and interest income in limited cases.
Detailed description of corporate residence rules in Singapore
taxsummaries.pwc.com
Your company is a tax resident of Singapore when its control and management is exercised in Singapore in the preceding calendar year.
www.iras.gov.sg
Claim tax benefits under an Avoidance of Double Taxation Agreement or treaty by applying for a Certificate of Residence or via a tax reclaim form.
www.iras.gov.sg