Good system to streamline the AP process

for my department specifically, we use Tipalti to process and pay incoming invoices from multiple vendors. We have an establish approval chain for all invoices and larger purchases require a higher level of approval. We also use it as a repository for to locate past invoices. Our specific use case is that we generally pay our shipping companies for equipment movements. Then, we will use the invoice to send the cost onto our clients whom we support with the equipment that we shipped. In the past it has been challenging to keep track of all of our shipping costs and to know exactly how to break down the costs per client.