Comment by drewsski

Given that you are processing that much volume, wouldn't it make sense to explore interchange plus pricing with a processor that connects directly to the card networks? I don't know much about the car rental business, but my experience has been that they typically require credit cards rather than debit cards. The ratio of debit to credit card usage obviously makes a big difference given that average credit card interchange cost hovers around 200 basis points while debit is closer to 50 basis points. If most of your transactions are credit card, then you're kind of stuck with the higher interchange rates even before Stripe adds their markup.

At my company, we started off with Stripe since the API's make it very easy to get started, but since then we have added backup integrations with Adyen and Fis. Stripe API's are still the gold standard, but as you have experienced, that vendor lock in limits your options when they decide to jack up prices.

For businesses that do recurring payments/subscription, one important consideration when you get started is whether you can port out the tokenized card data if you do decide to move to a different processor. Definitely don't want to have to ask subscribers to re-enter their card details because the payment details they provided via Stripe cannot be ported.