When one payer is most of your income

What it is: The share of your income that comes from your single largest payer.
Why it matters: Above about half, you do not have a business — you have one job with extra paperwork and none of the protections. One person's budget decision moves most of your year, and you will find out about it after it has been made.
The method: Take twelve months by payer. Divide the largest by the total. Above 50 per cent is worth naming out loud. It does not mean leave that client. It means find the second one before you need to.
Example: Danish had 60 per cent of his year from one studio, on no written contract. The work was good. The position was fragile, and the two facts had nothing to do with each other.

Above half from one buyer, and it is one signature away from a pay cut.

Now you

Name every payer and what each one paid across twelve months.