how can each different delivery site be traced if the same customer has 10 to 15 sites
You will have to create multiple customers with different delivery addresses to have access to all functionality for each site.
the problem is that they make payments from the same office. there is no estimate of how much money will be left.
You will need to be much more specific about exactly what you are trying to achieve.
You first asked about tracing delivery sites. What did you mean by that? I interpreted your question as a desire to obtain reports for each site, which means each will need to be a different customer.
Next, you expressed concern over estimating how much money is left. How much of what money?
I Have a few customers who have multiple site. If each of them did not consider that individual site as a separate customer, when that customer hives a check in conjunction with on of his many sites i do not understand which customer has to pay it to ageist. another problem is that there is no opportunity to export the invoices from this clients and how much the will bring
Have you tried creating a Custom Field on Sales Invoice for the delivery address?
When creating the Custom field be sure to select these boxes so that delivery address appears on the Sales Invoice and in the Sales invoice list.
If your customer does not designate which sales invoices are being paid, and does not indicate which site is involved, nothing in Manager will help you.
I assume the customer has one point of payment but multiple delivery addresses.
Manager does not support multiple delivery addresses.
The best you can do is put the actual delivery address in a custom field. For optimal layout you may also need a custom theme