Comment by epistasis

Today I accidentally transposed the first two digits on my CC number.

The form programmer had done some super stupid validation that didn't allow me to edit it directly. Every change moves the cursor to the end of the input. More than 16 characters could not be typed.

Any person who codes that PoS should have their software license revoked and never be allowed in the industry again. Far better to use a plain text input than all the effort used to make users lives hell.