> The process is slow, so bear with it and price for the delay of the funds.Every large company actually has two parallel ways of paying.
There's a main procedure which is extremely slow, because getting a 6 month interest-free loan from your suppliers is free capital, and maybe the supplier will forget and you won't need to pay at all which is free cash, and to access these benefits all you need is a smaller accounts payable department. They will be overjoyed to not pay you because you didn't submit form AB-1234 confirming that you have a policy on modern slavery. And they absolutely will not chase you for that form.
Then there's a parallel procedure, where your contact asks their boss's boss's boss's boss and the bill gets paid by credit card within the hour.
Having a reasonable amount of flexibility is fine - but at any time that friendly, helpful, trustworthy contact you're working with could change jobs, the project could be cancelled, or the project could end successfully and all your contacts get reassigned.
You don't need to extend so much credit that you'd be put in a difficult financial situation were they not to pay - if the client has reached their credit limit, and they are late on payments they're contractually obligated to make, you just need to get your contact to trigger the fast procedure instead of the slow one.