As a Service Company, most of our clients have an Invoice Address and a Site Address, we can create custom fields for our clients under 'Other Data' but we cannot actually add these custom fields to a Quote, Invoice or Statement...
This means we have to create each invoice manually instead of a batch file CSV... lot of additional extra work for what I believe is a basic requirement of good practice to make invoices easier for the client to understand what they are being billed for and at which address...