# Flexible Fees Any accepted tokens can be used as transaction fees on the Acala Network. Transaction fees are ultimately settled in the network native token ACA. Therefore a fee token must have a liquidity pool with the Acala stablecoin, which will create a route to the native token ACA. The system will automatically find the next available and supported fee token if the default token has zero balance. * Acala Network * Default fee token: ACA * Default order: ACA > aUSD > DOT > LDOT * Karura Network * Default fee token: KAR * Default order: KAR > kUSD > KSM > LKSM --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://wiki.acala.network/learn/flexible-fees.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.