It’s customary practice for clients to pay for every project. Each month, they’re billed for a corresponding amount of work and receive an invoice with payment details. There’s no pro-bono, but one client thought so.
A few years ago, after receiving the payment for the first month of work, a client stopped paying. Emails weren’t being replied to and voicemails weren’t answered. The account was frozen until they paid their invoice.
“We have to pay each month?” was their reply when asked why they haven’t paid.
The client had money, but only wanted to pay for one month of work (considering their contract was for a four month project, one payment was 1/4 of the total amount).
You wouldn’t do that with any other service (utilities, cable, phone, etc.), so why do it with this one? Eventually, they paid the full amount, but it was after being educated on the basics of billing.
In short, you have to pay every month. Feigning ignorance doesn’t count.