This has some useful information. You'll need to know what payment format/type they need and if they will be using addenda records. Also, you may need to plan your application to send what is known as a prenote for each new person you're sending a payroll deposit to. A prenote is a zero dollar transaction that is processed through the system to ensure that the bank account, bank aba (or routing transit) number are correct. I found the link below from doing a google search on create ach file. There is a nontrivial amount of new terms, etc involved in this. It may be difficult for someone to provide a sample without knowing what payment type, etc your customer needs. Also a sample may have bank aba numbers and bank account numbers which are typially confidential. good luck

http://chat.cashproweb.com/cpuniversity/portal/training/Technical_Resources/NACHA%20FORMAT_LNA%20and%20SFB.pdf