Can I revoke a permit signature that has not been used?

You cannot erase a signature from someone else’s possession. You may be able to make it unusable by changing the relevant nonce or authorization state, but the method depends on the exact permit scheme.

Identify the scheme before acting

ERC-2612 defines its nonce and deadline checks. Permit2 separately exposes allowance revocation and nonce invalidation, plus unordered nonce invalidation for signature transfers.

Why a zero allowance may be insufficient

An unused valid permit can potentially create or restore an allowance when submitted. Clearing the currently visible allowance is not necessarily the same as invalidating that permit. Likewise, removing token access to Permit2 can block transfers now without consuming every outstanding signature; later reapproval can change the situation.

Do not guess nonce values or run code from an unsolicited rescue message. Use a reputable, verified interface that explicitly supports the authorization you signed, or obtain help through the protocol’s official support.

Verify the result and remaining risk

Check confirmed onchain state and whether any transfer already occurred. An invalidation transaction can race with use of the signature. It cannot recover assets already moved.

Keep the full signature private while seeking help; share its type and nonsecret descriptive fields first. If the recovery phrase or private key was also exposed, signature cancellation alone is not enough because the attacker can create new authorizations.