We are a non-profit. We use classes to identify funders, so we can't use it for anything else. For example, to purchase a rototiller, we would use the class to allocate to the funder who will be covering the purchase costs. Same situation for the fuel we would purchase, the repairs/maintenance on the equipment (we have expense accounts for each of these) etc.  We are looking to rent the rototiller (for example) out to clients to help offset our costs. Our program manager wants to be able to use items during the 'pay bills' process to identify that the expense belongs to that equipment (as well as allocating to the funder). We would then also like to use that same item when we create a invoice to the client for the rental.  Our hope is that we can easily run a report that will list all the expenses that were associated with that item and then all the revenue it generated. We can then evaluate our rental fees for the future.  Perhaps we are asking for something that cannot be done that easily?  If you have a solution, we would really, really, appreciate it.