The mysterious "receipting team" is not in the main office, and has no phone number or even names listed, emails are never directly replied to, instead site contacts will call to relay questions/answers from them, ref# come from an automated do-not-reply email. They will quite often be "backlogged" and fail to send a ref# before the the end of the month, and suddenly will be cleared up on the 1st of the month.
We've had jobs that finished in the first week of a month, been ignored for 25 days, received a ref# with an apology for the delay on the 1st of the following month, get paid 45 days end of that month. So up to 100 days from completing work to getting paid. All our accounts are POS, 7 days EOM, or 30 days EOM, and must be paid on time or we lose supply. So to do a job with $100k of materials and wages for them, we have to have $100k spare cash for up to 60-100 days
It's not a cashflow problem, they're sitting on reserves and we're a blip on their radar, less than 1/10th of a percent of their outgoings
So we quote them outrageously high, and they never blink. I've told them some jobs would be up to 50% less if they paid quicker, and they've outright said they'd rather hold the cash and pay more. For a sense of scale we've invoiced them about $500k a year for the last few years, they've told me to clear out a couple weeks for two jobs that are nearly that much each, in February and April this year. I can't figure out who's getting the bad deal, them or me, I keep assuming they must have some massive upside I'm not seeing ¯\_(ツ)_/¯