I have worked extensively with Spanish lawyers to translate Spanish tax terms and believe that I can accurately say that there are no exact equivalents on either the the US or UK corporation tax forms.

For US tax forms see: http://www.irs.gov/formspubs/index.html?portlet=3

For UK tax forms see:
http://www.hmrc.gov.uk/businesses/tmacorporate-tax.shtml

Thus to avoid misinterpretations I would suggest the following descriptive renderings based on your definitions:

cuota íntegra = total tax due
cuota líquida = total tax due minus tax credits*
cuota diferencial = total tax due minus tax credits, taxes withheld and prepayments (amount payable or refundable)

*"deducciones sobre la cuota" are called "tax credits" in English

Hope you find this useful.