Hey Brian
I operated a sign and service installation company for 36 yrs. I did very well, but had excellent accounts. I had a couple of National Sign Companies, who we had an agreement that I got paid in 30 days with the 45 being the max. In return they got my instant attention and a better rate.
What I have learned, You need a line of credit large enough to sustain your business. Many companies will hold off your payment until they collect from their customer. Just remember you are not a bank, you need your money too.
Normally I made it clear that its 30 days, 45 days I'm on your A**.
I have been told , by my clients when I want payment, that they will not use me again and that is fine with me.
I lost one major retrofit account with a National here in Canada, because I would not install any more of their signs until I got paid, of course I had a lot of their product in my yard. They owed me 50K for over 90 going to 120 days.
I do need clients like these.
I am proud to say one of the large banks here in Canada, (The Royal Bank) has asked me to mentor other businesses.
Just remember, watch your accounts receivable, preferably COD or with a good deposit. Sign companies who hire you to do the install, receive a deposit before manufacturing, You must be part of the deposit also.
You have a skill that is in great demand and should be able to make a decent living off of it.
Dave