Do You Need A Pinpad To Process Debit?

No, any debit card that has the Mastercard or Visa logo on it can be
processed as a debit card through your credit card machine, point of sale
device, etc.
Also, a regulated debit card which has a substantially lower cost can also
be processed at the lower cost without a pinpad.
Pin-based debit which is processing a debit via a pinpad, can have lower
costs associated with processing that debit card. So there will be some
instances where having a pinpad is to your advantage.
Every business model is unique so we would look at your scope of customers
and clients and determine if using a pinpad is advantageous for you or if
you do not need one.