PMP Application Process - Reference Check

Toms

Newbie here and in the run for PMP. Wanted to understand if PMI will always do a reference check (100% of the time) irrespective of whether flagged for audit or not. I'm not in touch with several of my references and wanted to understand if I have to give a heads up to the references or is that necessary only if you are flagged for audit.

Also if foreign education a sure trigger for audit. I have my education from India and will be applying for the exam in US. Would appreciate any guidance / inputs.