Tap the Credits box at the bottom of the sidebar, or Plan & credits in the sidebar. On a phone, tap the menu button (≡) at the top right first. Then scroll to Credit history. Every change is listed with its reason and your balance after it.
Common reasons
Free credits reset to 50 every 30 days, and unused Free credits do not carry over.
A pass ended: unused pass credits end with it, and Free credits start.
Buying a pass on Free replaces your Free credits with the pass's credits.
A generation is running: its credits are taken when it starts and returned if it fails.
A podcast episode holds its credits while it is processed.
Two numbers
The Credits box in the sidebar shows your plan credits out of your plan's allowance, plus any top-up credits as a separate plus figure, such as 120/600 +100. Plan & credits shows the combined total, with "Includes [number] top-up credits" below it.
If something still looks wrong, contact us with your account email and what you expected to see.