1. A computer-implemented method for summarizing receipts and grouping the receipts onto one or more invoices, the method comprising: receiving a number of receipts and a time period including a start date and an end date; summarizing the receipts in the number of receipts having an approval date in the time period to obtain a number of summarized receipts; and grouping the summarized receipts to obtain one or more grouped invoices based on two of a number of grouping rules, the number of grouping rules including grouping by supplier pay site code, grouping by payment currency, grouping by receipt number, to grouping by payment term, grouping by value date, grouping by invoice type, and grouping by tax rules.