A token contract upgrade changes the code or address used by a token on a blockchain. The key condition is whether the upgrade keeps the token’s contract address or moves balances to a new one. An XMR bridge may support one token contract while leaving another unsupported, even when both have the same name.
Check whether the token kept its contract address
First, compare the old and new contract addresses on the token’s official announcement or blockchain explorer. A contract address is the token’s unique on-chain identifier; the token name and ticker alone cannot tell you which version you hold. The fast XMR bridge is a concrete example of a service used to swap XMR with other crypto assets, but token support still depends on the specific asset and network.
Some upgrades change a proxy’s underlying code while keeping its public address. A proxy is a contract that forwards calls to another contract, so wallets and services can keep using the same address. Other projects deploy a replacement contract and ask holders to move their balances. Ethereum.org describes this as contract migration; the new token then has a different address.
For the XMR-to-token part of a broader move, xmrbridge.app is a service for swapping Monero with assets such as BTC, ETH, and USDT. Its role as a swap service does not establish that every token contract version is supported.
Bridge support depends on the exact asset and network
A bridge or swap service must recognize the token contract it receives, not just its ticker. Operators may need to update their token records, deposit checks, and payout route for a replacement contract. Until those changes are made, a new token can be unsupported even if the project says the upgrade is complete.
For example, imagine you hold 1,000 units of a token on Polygon. The issuer announces a 1:1 migration, so 1,000 old units can become 1,000 units at a new address. That ratio describes the issuer’s migration; it does not mean a bridge will accept either contract or convert the old units automatically.
OpenZeppelin’s proxy documentation explains why an upgrade can keep the same address: the proxy stays in place while its implementation changes. That distinction is the useful check. If the address is unchanged, confirm the service recognizes the upgraded contract; if it changed, confirm the service explicitly supports the replacement address.
Confirm support before sending tokens
Check the chain, full contract address, and token version against the service’s stated support information before moving funds. If the new contract is not listed, ask the service or issuer whether it is supported and whether old tokens must be migrated first. Do not infer support from a matching ticker, wallet balance, or project announcement.
If you already sent a token that the service does not support, save the transaction ID, chain, contract address, and amount. Contact the service through its official channel and ask whether recovery is possible; recovery depends on how the deposit was handled, so it is not guaranteed. Avoid sending a second deposit as a test.
For an XMR bridge transaction involving a token that just upgraded, wait until the exact contract and network are confirmed as supported, then use the supported version.