Mastering Multichain: How to Move USDC and POL Across Blockchains

You might find a new decentralised finance (DeFi) platform (financial services built on blockchain networks rather than through traditional institutions) that looks ideal for your needs, then discover a practical issue. Your funds are on Ethereum, but the platform only supports Solana. In the early days of crypto, solving this usually meant sending funds to a centralised exchange, trading into a different asset, then withdrawing again, paying fees at each step.

Today, multichain technology gives you a more direct option. You can move value between networks without going through several intermediaries, provided you understand how the process works and what the risks are.

Understanding the multichain ecosystem

Most blockchains were originally built as closed systems. The Bitcoin network does not know what happens on Ethereum, and neither network can naturally interact with Solana. Each blockchain has its own rules, programming tools, and native tokens.

Multichain technology acts like connectors between these separate systems. It introduces interoperability, which means that different networks can share information, move value and coordinate activity.

This connectivity can be useful for many types of customers. Some blockchains focus on strong security and decentralisation but are slower and more expensive. Others are designed for high transaction throughput and very low fees, but may offer different security trade‑offs. A multichain approach lets you choose the network that best matches your current need for speed, cost and features.

How it works in practice

When you move a cryptocurrency from one blockchain to another, the token usually does not physically travel between networks. Blockchains are separate databases. They cannot simply hand tokens to each other.

Instead, they use special systems known as cross‑chain bridges. These bridges coordinate actions on two or more networks to give the effect of a transfer.

Here are some of the most common bridge mechanisms and how they work:

• Lock and mint
  You send your tokens to a smart contract on the source blockchain. This contract locks your funds in a digital vault. A verification system confirms that the deposit happened, then instructs the destination blockchain to create a wrapped version of your token.
  Wrapped tokens are digital representations of your original asset on a different chain. They are designed to track the value of the original token, as long as the locked funds remain secure on the source chain.

• Burn and mint
  This method is often used by stablecoins. Instead of locking the token on the source chain, the protocol destroys (burns) it. A new token is then created on the destination chain.
  Because there is no large vault holding customer funds, there is less value stored in a single place, although other types of risk may still exist.

• Cross‑chain messaging
  Newer interoperability protocols do not just move tokens. They can send structured messages between blockchains.
  For example, you might sign a transaction on one network that tells a smart contract on another network to execute a trade, open or close a loan, or submit a governance vote.

In every case, you are relying on the bridge and its security model. It is important to understand that different bridges can work in very different ways.

Moving assets across chains with CoinJar

CoinJar supports selected networks for certain assets, which can make it easier to interact with multichain environments. Two common examples are moving USDC and POL to manage transaction speed and cost. Availability of specific networks and tokens can change, and may differ by country. Always check the current options in your CoinJar account.

Adding USDC to your CoinJar account

USDC is a widely used stablecoin that exists on multiple blockchains. You can deposit USDC into your CoinJar Ireland account from supported networks, however, due to current regulations, USDC cannot be transferred out of the CoinJar platform. Once your USDC is in your CoinJar account, you can cash it out to euro or swap it for another supported cryptocurrency directly on the platform.

When deciding to moveUSDC into your Coinjar account, consider:

• Solana
  Solana usually offers very fast transaction speeds and relatively low fees. During periods of heavy usage, you may experience congestion or temporary delays.

• Ethereum
  Ethereum is often slower and typically has higher transaction fees, especially when network demand is high. However, it is one of the most established smart contract networks and is commonly used for larger transfers and long‑term positions.

Note: Solana deposit addresses were updated in 2025, and legacy addresses no longer work as of 1 September 2025. Always ensure you're using current addresses for Solana USDC transfers.

Transaction fees, exchange rates, supported networks and processing times can vary. Always check these before confirming any transfer.

Moving POL on the Polygon network

Polygon is a scaling solution that works alongside Ethereum. You can think of Ethereum as a busy main motorway. Polygon is like an extra lane that helps move some of the traffic more efficiently.

POL is the upgraded native token of the Polygon network, replacing the former MATIC token in 2024. Polygon processes many transactions separately from Ethereum, then sends batched results back to Ethereum for final settlement. This can reduce the load on Ethereum and lower energy use per transaction. In practice, using Polygon often means faster confirmation times and much lower fees compared with using Ethereum mainnet directly.

CoinJar supports transfers of POL on the Polygon network, subject to availability in your region.

To send POL via Polygon using CoinJar:

1. Go to the "Send" section in your CoinJar account.
2. Choose POL as the asset you wish to transfer.
3. Select Polygon as the network, if multiple networks are available.
4. Enter a wallet address that explicitly supports POL on Polygon.
5. Double‑check that the network and address match.
6. Review the fees and confirm the transfer.

Using Polygon can be especially useful for frequent transactions or smaller transfers. On Ethereum, network fees for a single transaction can sometimes reach several Euros or more, depending on network activity. On Polygon, fees are often a fraction of a cent equivalent, although they are still subject to change.

Risks and how to stay safe

Multichain tools can be useful, but they also introduce extra layers of risk. Historically, several of the largest crypto hacks have involved cross‑chain bridges.

In lock‑and‑mint systems, significant amounts of cryptocurrency are stored in one or a few smart contracts. If an attacker finds a weakness in the bridge code or its validation process, they might drain these vaults. If that happens, wrapped tokens on the destination chain can lose their backing and may no longer hold value.

No bridge or network is completely risk‑free. However, you can take practical steps to reduce your exposure:

• Send a small test amount first
  Before moving a large sum to a new wallet or new network, send a small amount, wait for confirmation, and verify that it arrives correctly.

• Verify network compatibility
  Always check that the token, address, and selected network all match. For example, sending tokens on Ethereum to an address that only supports Solana can lead to permanent loss of funds.

• Secure your CoinJar account
  Secure your CoinJar account with a strong, unique password and enable Enhanced Security (two-factor authentication). We recommend using an authenticator app such as Google Authenticator or Authy rather than SMS codes, which are vulnerable to interception. If you use the CoinJar app, also enable passcode and biometric authentication to protect transfers.

• Research the infrastructure
  If you use external bridges or protocols, consider the size of the project, how long it has been running, whether it has been audited, and whether it publishes clear security information. No audit is a guarantee, but established and transparent projects may offer better risk controls than untested alternatives.

• Be cautious with large amounts
  For significant sums, some customers prefer slower or more established routes, or split transfers into smaller parts to limit potential loss from a single technical error.

Remember that you are responsible for your own due diligence. If a transaction is sent to the wrong network or address, there is often no way to reverse it.

Why multichain matters

Interoperability helps move crypto away from isolated islands of activity. Instead of each network competing for customers in complete separation, multichain technology encourages connection and shared liquidity.

For developers, this can mean building applications that interact with assets and customers across several networks at once. For everyday customers, it can mean a smoother experience, where the choice of blockchain is driven by practical needs such as speed, cost and the services you want to access.

In time, the technical details of which chain you are using may become less visible. What should remain clear, however, is the need to understand the tools you rely on, compare risks and costs, and move assets between networks carefully.