# `invalid_exact_evm_failed_to_verify_signature`

> The facilitator could not complete signature verification. What causes this x402 error and how to fix it.

The facilitator could not complete signature verification.

|  |  |
| --- | --- |
| Reported by | the facilitator, during verify |
| Usually fixed by | the buyer or the seller, depending on the cause |

## Cause

The facilitator needs to read the payer's account code from the chain to decide how to verify the signature, and that lookup failed. It says nothing yet about whether the signature is good.

## Fix

- Retry after a short wait; this is usually an RPC problem on the facilitator's side.
- If it persists, try another facilitator for the same network.

## About this reference

Causes are taken from the source of `@x402/evm` 2.31. Other facilitators and later versions may use the same code for slightly different checks. See [all x402 errors](https://x402testendpoint.com/errors).

Source: https://x402testendpoint.com/errors/invalid_exact_evm_failed_to_verify_signature