These are the online filing systems for the USA, Canada and United Kingdom. Access to the Public Company filings such as Annual Reports, etc are a click away. Most countries have some degree of online access.
https://www.sec.gov/search-filings
A secure, web-based system that allows market participants to file, disclose, search for information in the United State’s capital markets. It's a national system used by all market participants and is available 24/7
https://www.sedarplus.ca/landingpage/
SEDAR+ is a secure, web-based system that allows market participants to file, disclose, search for information, and make payments in Canada's capital markets. It's a national system used by all market participants and is available 24/7
https://find-and-update.company-information.service.gov.uk
Registers and maintains information on all UK limited companies and limited liability partnerships (LLPs)
Makes company information available to the public
SEDI is a mandatory disclosure system for insiders to report trading activities and for issuers to report events. Issuers must file a profile supplement within three business days after becoming an issuer.
This is the sister website to the Sedar filing system, it allows you to map out the parties involved in every Canadian public company. Incredibly valuable in the smaller market value space.