The key cost benchmark here is the cost per invoice, and the main challenge lies in defining a comparable core activity to benchmark, and making allowances for the very different range of payments involved. The definition adopted by this club is that the core creditors activity starts when invoices are input to the computer. This excludes most of the work undertaken in local departments, but must include the cost of local data input, which can be an important element in the total cost, and may be hard to estimate.

The other difficulty is the wide range of different transactions that can be counted as ‘invoices’. For example processing a benefit payment as specified by the benefits system involves much less work than paying a commercial invoice. The type of workload can therefore heavily affect cost per invoice comparisons.

There is no simple solution to this problem; however participants can benefit from the wide membership of these clubs by selecting for comparison other members who have a similar type of workload. Other comparisons include the methods of payment, the number of incorrect payments, and the percent paid on time.