I've been self-employed for a long time but I've been lucky enough to work for companies who've paid on time.
This past year has been dire work wise but I ended up working for an old client for the last quarter (not full time, but enough).
Their payment terms are already longer than mine. However, on the day the most recent payment was due, they emailed to say they couldn't pay me on time due to a number of their clients paying them late. The invoice is sizeable.
They are a good sized company.
I've been pestering them for a payment date but they won't commit, just said it will likely not be until the end of this month (5 weeks late). By then, another invoice will be due and another invoice will have gone in. I'm still doing bits of work for them, tying something up, but I rejected offer of new work until this is resolved. Equally, I really like the work and the team on the ground and I don't want to lose what might be a lucrative income stream this year (in a dry industry).
That said, I'm doing it for money!
I want to believe it's a matter of cash flow for them - although I'm shocked they don't have a line of credit for these matters - but when do you start to worry the company is in trouble?