Sorry to hear about your loss,but I think we all need to change our mind set in these times.
Check out their credit rating no one would give me credit or cash without it,you can even insure against loss.
we can change our payment terms,payment in 14 or 7days with a discount,or like the commercial customer I booked in on Friday I just said I expected payment on completion which was agreed.
If they have not got the money before you do the job how come they will have it in say 30 days ?
I do'nt like working for nothing so check out if you want to business with them first, and of course cash is king. :

Regards Hotsteam