Don't panic; your coins are safe. Usually, when you can't see your tokens in Phantom, it is because they were sent on a blockchain that Phantom does not currently support.
Many blockchains use Ethereum's wallet standard, such as Binance Smart Chain and Avalanche, and all Ethereum layer 2 rollups, such as Base and Arbitrum. Your wallet address is the same across all these chains.
Phantom, however, does not support all of these chains. The wallet only supports Ethereum, Polygon, Solana, and Bitcoin. So, if you send tokens on a different chain, they will not appear in your Phantom wallet.
Accessing your tokens is simple. You just need to install a wallet that supports the blockchain on which they are located — such as Metamask — and import your Phantom wallet's 12-word seed phrase. Here are the steps:
1) Install Metamask
2) Click "import an existing wallet" and input your Phantom's seed phrase.
The next step is to add the blockchain your tokens reside on to your new Metamask wallet.
3) Click the Ethereum symbol in the top left corner of the wallet.
4) Click "add network."
5) Select the blockchain where your tokens reside.
Hopefully, the blockchain you need is listed under "Popular custom networks." If not, click "Add a network manually" and enter the chain's details. This Coindesk article will help guide you.
Now, you should see your tokens in your new Metamask wallet. To transact on this blockchain, you'll need a small amount of its native token to pay gas fees.
Here are some options if you'd like to bridge your tokens to Solana.