When moving assets from Avalanche® back to Bitcoin, the bridge charges an in-kind transfer fee. The user interface does not allow transfers of less than the fee amount. If a user manually generates and issues such a transaction, the bridge will mark the transfer as invalid and not process it.
For a more in-depth read on how the Avalanche Bridge™ works, please read the following articles.
For any additional questions, please visit our knowledge base or contact a support team member via the chat button at support.avax.network.