A device, preferably of credit card thickness and possessing credit-card utility by way of a magnetic swipe for determining portioned fees to paid by each of a multiplicity of entities "1-n" acquiring a number of items "1-x" presented under a single invoice having a CPU for determining calculations and receiving information relative to each of "1-n" and "1-x" for each of the entities; a display for displaying the items and fees for each of said entities; an information storage and retrieval system for storing for each of the number of entities "1-n" and items "1-x," the cost for each item, tax to be applied for each item, the tip to be applied for each item, and summing for each item as well as the total for all entities; review of the invoice against the sum of all entities; and comparison for comparing the invoice against the sum. The device is utilized for food available to be purchased by way of a menu in a restaurant and items available from a store. The device also includes a method for determining portioned fees to paid by each of a multiplicity of entities "1-n" acquiring a number of items "1-x" presented under a single invoice, having an invoice total to one or more of the entities; one of the entities "1-n" enters one of the items of "1-x" by description; the one of the entities enters the cost of the item; the of the entities enters the tax and/or tip on the item; the are repeated until "n" is reached; and upon reaching "n" the sum is displayed and verified against the invoice.