The stages of getting an invoice paid

1: send invoice

2: day before invoice due, get an email asking me to complete a four page long Supplier Form.

3: a week later, another email asking for a company letterhead. Create doc solely for this purpose, because it's not 1998 anymore

3: A week later, get email asking for a bank statement

4: A week on, another email asking for scan of photo ID

...

...

26: Phone company reminding them it is now a month overdue, be promised it's in the next run

27: Check bank account...