diff --git a/src/interfaces/IMultiplier.sol b/src/interfaces/IMultiplier.sol
new file mode 100644
index 0000000..117f10b
--- /dev/null
+++ b/src/interfaces/IMultiplier.sol
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+interface IMultiplier {
+    /// @notice Returns the voting multiplier for `user`.
+    function getMultiplyingFactor(address user) external view returns (uint256);
+
+    /// @notice Returns the validity period of the multiplier for `user`.
+    function validUntil(address user) external view returns (uint256);
+}