# Burning debt

When an TON staker wants to exit the system or reduce their debt and unlock staked TON, they must pay back their debt. At its simplest: a staker mints 10 syUSD by locking TON as collateral, and must burn 10 syUSD to unlock it. But if the debt pool fluctuates (and therefore their individual debt fluctuates) while they are staked, they may need to burn more or less debt than they minted. The process for reducing debt to zero is as follows:

* The Syde contract determines their debt balance
* The required amount of syUSD is burned, and total supply of syUSD is updated along with the syUSD balance in the user’s wallet.
* Their TON balance becomes transferrable.
