The error
Faucets word this differently, but these are the same problem:
Invalid address.
Please enter a valid testnet address.
Address not recognised for this network.
Why it happens
You've pasted an address the faucet's validator doesn't accept for that network. The common causes are a mainnet address where a testnet one is required, the wrong address type on a chain that has several, or a chain with two address families where the faucet only serves one.
How to fix it
- Bitcoin testnet: several faucets reject SegWit (tb1…) addresses and only accept legacy m…/n… or P2SH 2… addresses. This is the single most common cause of a rejected BTC testnet claim.
- BNB Chain: the faucet accepts Smart Chain (0x…) addresses. A Beacon Chain (tbnb…) address is a different chain — bridge with Binance Wallet if you need it there.
- Cardano, NEAR and Algorand: testnet addresses are distinct from mainnet ones. Generate the address from a wallet explicitly set to testnet/preprod rather than converting a mainnet address.
- Check the network on the per-token page. The comparison table names the exact network each faucet dispenses on — an Amoy address will not work on a Sepolia faucet.