Does a email request work as documented contact for non payment. I have them admitting that they owe me. Never got payed. Been 4 months.
It depends upon the state. In some states, the certified letter return receipt starts a statutory process in which they must answer within a certain number of days. And it provides a paper trail. Try again and put SECOND REQUEST at the top of the page.
A little more detail is required for the best response. As @M_Barnes stated, a certified letter may be required if there is a statutory issue. If this is a production/sales issue, then email may be sufficient with a little diligence. I prefer to use email threads with many companies to indicate that I am diligently attempting to resolve an issue. When dealing with owner relations, you need to recognize that you may be trying to work with sub-contract services which generally delays the process. Good luck.
Thank you and miss Barnes for your input