I've seen this plenty before, but all my searches bring up old answers and varying numbers.
I'm currently on a JB plan but want to port away and then port back in to get the sign-up credit. How long do they currently need you to be gone before you're considered a "new customer" and eligible for the credit? Is it 30 days, 90 days, 365 days?
Been a while but when I did it last it was 30 days.
It was the worst 30 days with Optus ever.