How to send crypto safely: addresses, networks, fees and the mistakes you can't undo

Sending crypto is quick, but it’s also unforgiving. There’s no bank to call and no “undo” button. ethereum.org is clear: once a transaction is confirmed, you cannot cancel it. Bitcoin.org says the same about bitcoin: a transaction can’t be reversed, only refunded by the person who received it.

Most losses come from a handful of avoidable mistakes. This checklist covers them, whether you’re moving coins between your own wallets, withdrawing from an exchange or paying someone.

The five-step checklist

1. Copy or scan the address, never type it.
2. Check the whole address, character by character.
3. Choose the right network.
4. Make sure you can pay the fee.
5. Send a small test amount first.

The sections below explain each one.

1. Get the address right

An address is like an account number for crypto. ethereum.org advises you to avoid typing any address manually, because it can easily lead to errors and lost funds. Instead:

• Copy and paste the address from the recipient’s wallet or the exchange’s deposit page.
• Or scan the QR code, which avoids typing altogether.

Then check it. Malware exists that swaps an address in your clipboard for the attacker’s, so compare what you pasted with the original.

Watch out for address poisoning

A newer trick targets the habit of checking only the start and end of an address. The scam is described in a draft Ethereum standard (ERC-8117):

1. The attacker watches your transaction history.
2. They create a lookalike address that matches the first and last characters of one you use.
3. They send you a zero-value transaction from it, so it appears in your history.
4. Later, you copy the wrong address from your history and send funds to the attacker.

Wallets often shorten addresses on screen, like 0xd28b…6922, so the middle characters, where the difference is, are hidden. The FBI has warned about a related scam that uses tokens impersonating well-known stablecoins, sent from addresses that closely resemble ones victims have used before.

The fix: don’t copy addresses from your transaction history. Save trusted addresses in your wallet’s address book, or copy them fresh from the source, and check the entire address.

Know what an address should look like

Different kinds of address follow published formats, and each includes a checksum that helps wallets spot typos:

Two practical points:

• Bitcoin mainnet addresses in the bc1 format always start with “bc”; testnet ones start with “tb”. BIP 173 says wallets must check this, which helps prevent sending real bitcoin to a test address or vice versa.
• Ethereum’s checksum relies on the capitals. ERC-55 says that a randomly mistyped address will pass the check only about 0.0247% of the time. The check depends on the mix of capital and small letters, so copy and paste rather than retyping.

A checksum catches typos, not fraud. A scammer’s address, or a poisoned lookalike, is perfectly valid.

2. Use the same network

The same token can exist on several blockchains. A stablecoin, for example, may be issued on Ethereum and on other networks. ethereum.org warns that when transferring tokens, you must make sure the recipient is using the same network as you, because these are not interchangeable.

In practice:

• On an exchange’s withdrawal page, select the network that matches the destination.
• On the receiving side, check which network the deposit address is for.
• If the deposit page shows a memo or tag, include it: some exchanges need it to credit your account.

When in doubt, stop and check before sending. See CEX vs DEX for how exchanges and wallets differ.

3. Make sure you can pay the fee

Every transfer pays a network fee:

• Ethereum and tokens on it: fees are paid in ETH, even when you send a stablecoin. ethereum.org says to make sure your wallet holds enough ETH to cover the fee, which varies with network conditions. Most wallets suggest a fee automatically.
• Bitcoin: Bitcoin.org explains that if you pay a fee below what the network is currently prioritizing, the first confirmation may take considerably longer.

Exchanges also charge their own withdrawal fees. See exchange fees explained.

4. Send a test amount first

For any new address, or any large amount, send a small amount first. Wait until it arrives, check it’s in the right place, then send the rest. The extra network fee is a small price compared with losing everything to a typo or the wrong network.

5. Wait for confirmations

A transaction isn’t final the moment you press send. It has to be included in a block, and each new block on top adds a confirmation.

• Bitcoin: new blocks arrive about every 10 minutes on average, but Bitcoin.org notes that block discovery is probabilistic, so a confirmation may come much sooner or much later. Its guide describes one confirmation as somewhat reliable, three as mostly reliable and six as the minimum for high-value transfers.
• Ethereum: ethereum.org says a transaction might take from a few seconds to a few minutes, depending on how busy the network is.

Exchanges set their own number of confirmations before crediting a deposit.

Receiving crypto

• ethereum.org says it’s safe to share your receiving address with anyone.
• With a hardware wallet, check the receiving address on the device’s own screen, not just on your computer. See hot vs cold wallets.
• Remember that blockchains are public. Bitcoin.org notes that anyone can see the balance and transactions of any bitcoin address. Don’t link an address with large holdings to your identity publicly.

Unknown tokens in your wallet

Tokens you didn’t ask for can appear in your wallet. ethereum.org explains that scam tokens can copy the name and symbol of real ones, but can’t use the same contract address, and recommends checking the contract address on the organization’s own website. Don’t try to sell or “claim” unknown tokens: that’s how many scams start. See crypto airdrops explained.

If something goes wrong

• Wrong address: if it belongs to an exchange or a person you know, contact them immediately with the transaction ID.
• Wrong network to an exchange: contact the exchange’s support. Recovery depends on the platform.
• Sent to a scammer: stop sending, save the details and report it. See crypto scams and where to report them.
• Beware of “recovery” offers. People who promise to get your crypto back for a fee are very often scammers themselves.