diff --git a/README.md b/README.md
index a9b84f17..847da8d5 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,5 @@
 # zkevm-commonjs
+
 Javascript library implementing common utilities for polygon-hermez zkevm
 
 [![Main CI](https://github.com/0xPolygonHermez/zkevm-commonjs/actions/workflows/main.yml/badge.svg)](https://github.com/0xPolygonHermez/zkevm-commonjs/actions/workflows/main.yml)
@@ -6,11 +7,13 @@ Javascript library implementing common utilities for polygon-hermez zkevm
 > **WARNING**: All code here is in WIP
 
 ## Usage
+
 ```
 const zkevmCommon = require("@0xpolygonhermez/zkevm-commonjs");
 ```
 
 You will find the following modules inside the package:
+
 - `Constants`: zkevm global constants
 - `contractUtils`: zkevm smart contract utils
 - `Processor`: class to add transactions and process them
@@ -27,13 +30,34 @@ You will find the following modules inside the package:
 - `mtBridgeUtils`: Merkle tree bridge utils
 
 ## Test
+
 ```
 npm run eslint & npm run test
 ```
 
+## Note
+
+In order to test, the following private keys are being used. This keys are not meant to be used in any production environment:
+
+- private key: `0x28b2b0318721be8c8339199172cd7cc8f5e273800a35616ec893083a4b32c02e`
+  - address: `0x617b3a3528F9cDd6630fd3301B9c8911F7Bf063D`
+- private key: `0x4d27a600dce8c29b7bd080e29a26972377dbb04d7a27d919adbb602bf13cfd23`
+  - address: `0x4d5Cf5032B2a844602278b01199ED191A86c93ff`
+- private key: `0x1d0722aff4b29780e9a78e0bf28d5e127fb276cfbb0c3eb6a0e1728401777f17`
+  - address: `0xeB17ce701E9D92724AA2ABAdA7E4B28830597Dd9`
+- private key: `0xd049e68efa0d85a3824c0b79f6817a986bb0cb3a075bcc2699118eca881d70ce`
+  - address: `0x187Bd40226A7073b49163b1f6c2b73d8F2aa8478`
+- private key: `0x0b929d50d7fda8155539e6befa96ff297e3e9ebce4d908f570310bdf774cb32b`
+  - address: `0xabCcEd19d7f290B84608feC510bEe872CC8F5112`
+- private key: `0xdfd01798f92667dbf91df722434e8fbe96af0211d4d1b82bbbbc8f1def7a814f`
+  - address:`0xc949254d682d8c9ad5682521675b8f43b102aec4`
+
 ## License
-Copyright
+
+### Copyright
+
 Polygon `zkevm-commonjs` was developed by Polygon. While we plan to adopt an open source license, we haven’t selected one yet, so all rights are reserved for the time being. Please reach out to us if you have thoughts on licensing.
 
-## Disclaimer
+### Disclaimer
+
 This code has not yet been audited, and should not be used in any production systems.