Hi Mike, in Mexico using factoring for payables is a common practice especially in manufacturing. Banks and other financial institutions offer the service and companies use it to either extend their terms and improve their cash flow.
In most cases is a good alternative, that requieres a little extra admin work but is worth it.
You need to be aware of the following:
1) some companies will close a deal only if you agree to get paid using a factoring service absorbing the discount. You can negotiate in most cases not to pay for the discount.
2) The company might ask you to wait until your invoice is about to reach due date to request the benefit (a way for them to extend terms).
Hope this helps, Alfredo
Alfredo Puerta