* The specific college's admission policies: Each college has its own criteria. Some are more selective than others, and they may not accept all diplomas, even if they're accredited. They might prefer diplomas from specific institutions or programs.
* The type of diploma: A high school diploma is generally required for entry into most colleges. However, even within high school diplomas, there can be variations (e.g., GED, homeschool diplomas) that may or may not be accepted by all institutions. Diplomas from vocational schools or other post-secondary programs might be considered for credit transfer, but this varies greatly.
* The accrediting agency's recognition: For high school diplomas, regional accreditation is the most widely recognized. Regional accreditation agencies (like the six regional accrediting bodies in the US) are generally considered more prestigious than national accreditation. Colleges are more likely to accept diplomas from regionally accredited high schools. For post-secondary diplomas, accreditation from a recognized body in the relevant field is important for transferability.
In short, while regional accreditation for high schools significantly increases the likelihood of acceptance by colleges, there's no guarantee. It's crucial to check the specific admission requirements of each college you're applying to, regardless of the diploma's accreditation.