# Address Binding

## Background

EVM+ is live on Acala and Karura and EVM wallet is required to access its feature - such as transferring ERC20 tokens. Acala's EVM+ has built in feature to auto-generate and auto-bind an EVM address to the Substrate (Polkadot) address when needed, so it is seamless for users to use EVM features. As there is no private key for the auto-generated account, this account can only be accessed through Polkadot address on supported Dapps such as Acala/Karura.

For users with existing EVM account and want to bind this account to the Polkadot address instead, this document describes the process for user to bind their own EVM account.

## Video

{% embed url="<https://www.youtube.com/watch?t=261s&v=wG9NBydbM6Y>" %}

## Pre-Requisites

* MetaMask and Substrate Wallets, Substrate wallet not bound to any account.
* ACA in your Substrate Wallet and other tokens in your MetaMask wallet to pay for transaction fees.&#x20;

You can learn how to create a Substrate wallet by following any of these [guides](https://wiki.acala.network/get-started/acala-network/acala-account). You can learn how to send ACA to your Acala wallet by following this [guide. ](https://wiki.acala.network/integrate/integration/token-transfer)

You can learn how to create a MetaMask wallet by following this [guide](https://www.youtube.com/watch?v=GNPz-Dv5BjM).

## Address Binding

**Note there are a few restrictions of the bind feature by design:**

* **Binds can only be done between one Substrate and one MetaMask account**
* **Neither account can be previously bound to another account. Additionally, binding is final - there is no unbind feature.**

1\) Go to [Bind MetaMask](https://apps.acala.network/bridge/bind-address) in the Acala app. Click `Connect to MetaMask` and select the account you'd like to connect. Do the same thing for your Substrate account.&#x20;

![](/files/2Vu9NP0sy2P3H1YQp9eG)

2\) **Double check that you are binding the correct accounts because this action cannot be undone.** Click `Sign`.

If you are having trouble connecting your MetMask, you can either add it via [Acala](https://chainlist.org/chain/787) and [Karura](https://chainlist.org/chain/686) on ChainList, or manually add the Acala network by opening your MetaMask wallet and going to Settings-> Networks -> Add Networks and entering the following information:\
\
**Network Name:** Acala

**New RPC URL**`https://eth-rpc-acala.aca-api.network/`

**Chain ID:** 787

**Currency Symbol:** ACA

**Block Explorer URL**`https://blockscout.acala.network/`&#x20;

![](/files/Xy2NuEKuECvIoWdTlHIe)

\
3\) Click `Bind`. Remember that in order to bind, you must have `ACA` in your Substrate account. You can learn how to send ACA to your Acala wallet by following this [guide.](https://wiki.acala.network/integrate/integration/token-transfer)

![](/files/5D8G3zc86JwF0HP1AO9X)

4\) You should now see that your accounts have been successfully bound!

![](/files/sM00yowFsHrMDvMQqo6x)

## FAQ

#### Can I unbind and bind to a new account?

No. Once you bind two accounts together, you cannot unbind them. If you you'd like to use a different Polkadot account or a different Ethereum account, you'll need to create two new wallets.

**Do I need to keep both seed phrases?**

Yes. Please keep both seed phrases. If you ever need to recover all of your funds, you will need both sets of seed phrases.

**Where can I see the MetaMask address linked to my account?**

If you've already completed the binding process, click on your account in the upper right hand corner and then hover over the chain icon to see the linked MetaMask address.

#### What are the differences between auto-generated EVM address and binding my own EVM address?

There is no difference when you are using it within Acala/Karura, but binding your own EVM address gives you additional flexibility in interacting with your account using your EVM wallet such as MetaMask.

&#x20;

![](https://lh4.googleusercontent.com/-B-rHmeDut74rF-RdLbpe-1f4nztlMahvLPjQTuXAdWrEWU3MHw71Xi_MTF-VmUvzo7xK8MDliQj5e-UH0j6ndP8XekrOz0nYaYZf3P0bY4K1e3UibRGHdi20VvOnI5DpKv4JgiqT2eSQmKmxA)

**Why is MetaMask having trouble connecting to Acala?**

If you are having trouble connecting your MetMask, you can manually add the Acala network by opening your MetaMask wallet and going to Settings-> Networks -> Add Networks and entering the following information:\
\
**Network Name:** Acala

**New RPC URL**`https://eth-rpc-acala.aca-api.network/`

**Chain ID:** 787

**Currency symbol:** ACA

**Block Explorer URL**`https://blockscout.acala.network/`&#x20;


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