Why processors terminate accounts
Terminations almost always come from risk monitoring rather than a person reading your website. Typical causes are a chargeback ratio approaching or above card-scheme limits; a high refund rate; a sudden spike in volume; a product or business model that the processor's acceptable-use policy restricts; a mismatch between what you told them at signup and what you sell; customer complaints; links to another account that was closed; or a request for documents that went unanswered.
Aggregator platforms, which onboard merchants in minutes with light checks, are the most likely to terminate suddenly, because they rely on monitoring after the fact instead of underwriting up front. Dedicated merchant accounts can also be closed, but usually after warnings and a review.