99% take UK credit cards and issue a receipt ...... no Pin number is required...... never bothered with a tag myself as we avoid toll roads if we can unless they cut out large unmanageable conurbations that we need to bypass.
We always have cash just in case!
The tag does cut out the need for the front seat passenger to take charge of making the payment......leaning out of the window to reach the machine can be interesting if the driver makes a hash of stopping in the right place! Don't use the right hand lanes as lorries who have tags, will be thundering through these without stopping!
These right hand lanes are only for tag payment.
Most of the other lanes will accept tags, credit cards, debit cards or cash.
Some lanes usually on the left may have height restrictions, so beware if towing a caravan.