You would need a table for your customers that contained a primary key (autonumber will work) for instance:
Code:
tblCustomers
CustID CustomerName ----> other fields related to customers
1 Company A
2 Company B
I do not know the structure of your pricing/rates but I'm guessing you have different rates for different items so you would likely want a 'item' table that also had an autonumber primary key and then a 'customer item charge' table that would contain the CustID, the ItemID and have it's own autonumber field as it's primary key with a field for the cost for that item for that customer.