Our normal billing procedure is to send the invoice with the package. This is very popular with most of our customers because it allows the person receiving the order to "approve" receipt of the merchandise and the bill all at once.
Most companies send an invoice after the fact forcing either the user, purchasing department or accounting department to hang on to a packing slip and wait for the invoice to come in. Later someone has to get the packing slip and match it up to the invoice.
We can mail invoices as well but we feel our normal method is less redundant for our customers.

We can also collect invoices and send them out weekly or monthly depending on your needs. We also accept Visa, MasterCard, American Express and locally provide C.O.D. options.

In any case our terms are Net 30 days from the invoice date.