Safe Transaction Habits: Test Sends, Address Checks, and Allowances

Who This Is For

Anyone who sends cryptocurrency or interacts with DeFi platforms needs to develop safe transaction habits. One mistake—sending to the wrong address, approving a malicious contract, or miscalculating gas fees—can result in permanent loss of funds. This guide covers practical habits to prevent these errors.

⚠️ Key Risks

Transaction reality check:

Crypto transactions are irreversible—once sent, funds can't be recovered
There's no bank or company to dispute transactions or request refunds
One wrong character in an address means funds sent to the wrong place forever
Unlimited token allowances can let malicious contracts drain your wallet

The Golden Rules

Before we dive into specifics, here are the non-negotiable rules:

Transactions are final: No undo, no chargebacks, no customer service to help
Verify everything: Addresses, amounts, fees—all of it
Start small: Test with small amounts before large transfers
Never rush: Urgency is a red flag, scams rely on pressure
When in doubt, wait: Better to miss an opportunity than lose funds

These rules sound simple, yet people violate them every day and lose funds.

Address Verification

Why It Matters

Crypto addresses are long strings of characters:

Bitcoin: 26-35 characters (e.g., bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq)
Ethereum: 42 characters (e.g., 0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb)

One wrong character = wrong address = funds gone forever.

Address Poisoning Scam

Scammers have gotten creative with addresses:

How it works:

You send funds to a legitimate address
Scammer monitors blockchain for your transaction
Scammer sends you a tiny amount (dust) from an address that looks similar to the one you just used
When you next send funds, you copy from recent transaction history
You accidentally copy the scammer's similar-looking address
You send funds to scammer instead of intended recipient

Example:

Real address: 0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb
Poison address: 0x742d35...similar characters...95f0bEb

Note: First and last few characters match—easy to mix up if you're not careful.

Safe Address Verification Habits

1. Check Multiple Points

Don't just check first and last few characters. Verify:

First 6 characters
Last 6 characters
Random middle section

Or better yet, check the entire address character by character.

2. Use Address Book / Whitelist

Most wallets and exchanges let you save addresses:

Save verified addresses with labels
Use saved addresses instead of copying/pasting
Double-check label matches intended recipient

Many exchanges offer withdrawal whitelisting:

Only allows withdrawals to pre-approved addresses
Requires waiting period (24-48 hours) to add new addresses
Provides time to catch unauthorized changes

Enable this feature. The inconvenience is worth the protection.

3. Test Sends

Before sending large amounts:

Send tiny amount first ($5-20 worth)
Confirm recipient receives it
Verify address one more time
Then send the full amount

Cost: Small extra fee for test transaction

Benefit: Prevents sending $10,000 to wrong address

Trade-off: Always worth it for significant amounts.

4. QR Codes When Possible

For in-person or same-device transfers:

Use QR codes instead of typing addresses
Reduces human error
Still verify address after scanning

5. ENS / Readable Names (Ethereum)

Ethereum Name Service (ENS) lets you use human-readable names:

Instead of: 0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb
Use: username.eth

Benefits:

Easier to verify
Harder to fat-finger
Can see what the address represents

Caution:

Still verify the underlying address
Scammers create similar ENS names (username.eth vs usernаme.eth with different character)
Not all wallets support ENS

6. Never Trust, Always Verify

Don't trust addresses from:

Discord/Telegram messages (even from "verified" users)
Email (could be phishing)
Twitter DMs
Screenshots

Always verify through independent source:

Official website (bookmark it)
Direct communication with recipient
Published donation addresses on official sites

⚠️Clipboard Malware

Some malware monitors your clipboard and replaces copied crypto addresses with the attacker's address. Always verify the pasted address matches what you copied. Consider this when copying addresses.

Address Checklist

Before sending funds:

[ ] Verified entire address (not just first/last characters)
[ ] Checked address against saved contact or independent source
[ ] Confirmed with recipient if sending to new address
[ ] Tested with small amount first (for large transfers)
[ ] Double-checked network (sending Bitcoin on Bitcoin network, not another chain)

Amount and Fee Verification

Double-Check Amounts

Common mistakes:

Extra zero (sending 10 ETH instead of 1 ETH)
Wrong decimal place (sending 0.01 BTC instead of 0.1 BTC)
Wrong token (sending USDC instead of USDT)

Prevention:

Type amount carefully
Verify on confirmation screen
Calculate: "Am I sending the amount I intend?"
For large transfers, use calculator to verify

Understand Network Fees (Gas)

Ethereum gas fees can be confusing:

You're sending $100 worth of tokens, but the transaction costs:

Low traffic: $2-5 in gas
Medium traffic: $10-20 in gas
High traffic: $50+ in gas

For small transfers, fees can exceed transfer value.

Tips:

Check gas fees before sending
Consider batching transactions (send once instead of multiple times)
Use gas tracking sites (etherscan.io/gastracker) to time transactions
Consider Layer 2 solutions for cheaper fees (Polygon, Arbitrum, Optimism)

Don't:

Rush transactions during peak times
Send many small transactions (fees add up)
Accept default "fast" fee without checking

More info: Fees and Transfers: Understanding Costs

Network Selection

Critical: Ensure you're sending on the correct network.

Example problem:

You want to send USDT to someone
You have USDT on Ethereum network
Recipient gives you their Binance Smart Chain (BSC) address
You send USDT-Ethereum to BSC address
Funds may be lost or difficult to recover

Each network has different:

Address formats
Transaction fees
Confirmation times
Token standards

Before sending:

Confirm which network recipient expects
Verify your tokens are on that network
Use correct network in wallet
If networks don't match, use bridge (carefully) or exchange

💡When Networks Don't Match

If you need to send tokens on a different network than you have them, the safest approach is: send to centralized exchange (on network you have), withdraw from exchange (on network recipient wants). This avoids cross-chain bridge risks.

Understanding Token Allowances

This is technical but crucial for DeFi users.

What Are Token Allowances?

When you use DeFi platforms (Uniswap, Aave, etc.), they need permission to move your tokens:

You can't just send tokens to smart contract. You must:

Approve the contract to spend your tokens
Then interact with the contract

This two-step process creates a permission called an "allowance."

The Risk

When you approve a contract, you typically specify an amount:

Approve exactly what you need (e.g., 100 USDC)
OR approve unlimited amount (common default)

Unlimited approval means:

Contract can spend any amount of that token from your wallet
Now and in the future
Until you revoke the approval

If the contract is malicious or gets hacked, unlimited approval lets it drain your wallet.

Real Scenario

You want to swap 100 USDC for ETH on Uniswap:

Step 1: Approval

Uniswap asks permission to spend USDC
Default approval: Unlimited
You approve (clicking button in MetaMask)

Step 2: Swap

Uniswap uses permission to take 100 USDC
Sends you ETH in return

Result:

Your swap succeeds
But Uniswap still has permission to spend unlimited USDC
If Uniswap contract were compromised, attacker could drain your USDC

That's the trade-off.

Safe Allowance Practices

1. Approve Only What You Need

Instead of unlimited approval:

Set approval to exact amount you're using (100 USDC)
Requires new approval for each use
More gas fees, but safer

How:

In MetaMask, click "Edit Permission" before confirming
Change "Spending Cap" from "Unlimited" to specific amount

2. Revoke Unused Approvals

Periodically clean up old approvals:

Tools:

Etherscan Token Approvals: etherscan.io → Connect wallet → Token Approvals
Revoke.cash: revoke.cash
Approved.zone: approved.zone

Process:

Connect wallet to tool
See all active approvals
Revoke approvals for contracts you no longer use
Costs small gas fee per revocation

When to revoke:

After you're done using a DeFi platform
For platforms you tried once and don't use anymore
For any contract you don't recognize
For platforms that seem suspicious

3. Use Separate Wallets for DeFi

Strategy:

Wallet 1: Long-term holdings, minimal approvals
Wallet 2: DeFi interactions, limited funds

If Wallet 2 gets compromised, Wallet 1 remains safe.

4. Only Approve Trusted Contracts

Before approving:

Verify you're on the legitimate website
Check URL carefully (phishing sites are common)
Research the contract if it's new/unknown
Read what transaction says on wallet screen

Never approve:

Contracts from links in Discord/Telegram DMs
Sites that look suspicious
"Urgent" approvals
Anything you don't understand

⚠️Approval ≠ Transaction

Approving a token allowance doesn't move funds immediately—it gives permission. The actual movement happens in subsequent transactions. But that permission remains until you revoke it.

Transaction Confirmation Habits

Read the Wallet Prompt

When confirming transactions, your wallet shows details:

Recipient address
Amount
Gas fee
For contracts: function being called
For tokens: token contract address

Don't blindly click "Confirm."

Check:

Does recipient address match what you expect?
Is amount correct?
Is fee reasonable?
Does this transaction make sense for what you're trying to do?

Hardware Wallet Verification

If using hardware wallet:

Device screen shows transaction details
Verify address, amount, fee on device
Device can't be fooled by malicious websites

More: Hardware Wallets: When They Make Sense

Transaction Speed Settings

Most wallets offer speed options:

Slow: Low fee, slower confirmation
Normal: Standard fee, standard confirmation
Fast: High fee, faster confirmation

For most transactions, Normal is fine.

Use Fast only when:

Time-sensitive arbitrage or trading
Network is congested and you need confirmation soon

Use Slow when:

Not time-sensitive
Network is quiet
Want to save on fees

Don't:

Always use Fast (waste money on fees)
Use Slow during network congestion (may take hours or days)

Common Transaction Mistakes

Mistake 1: Sending to Exchange Without Memo/Tag

Some cryptocurrencies require a memo/tag in addition to address:

XRP (Ripple): Destination Tag
XLM (Stellar): Memo
Some exchange deposits: Memo or Tag

Without the memo/tag:

Exchange receives funds but can't credit your account
Recovery requires contacting support (slow, may have fees)

Always check if memo/tag is required.

Mistake 2: Sending Test Transaction to Same Address

Scam variation: You send test amount, it arrives successfully. You send large amount to same address—but scammer has since replaced the address in your clipboard with theirs.

Prevention:

Don't copy address from clipboard for main transaction
Copy fresh from trusted source
Verify address again even for second transaction

Mistake 3: Wrong Network

Sending tokens on wrong blockchain:

Sending ERC-20 token to BEP-20 address
Sending Bitcoin to Bitcoin Cash address
Using wrong Layer 2 network

Result: Funds lost or difficult to recover.

Prevention: Confirm network with recipient before sending.

Mistake 4: Trusting Transaction History

Don't copy addresses from wallet transaction history:

Could be from address poisoning attack
Could be address you sent to once but is now compromised
Always verify addresses independently

Mistake 5: Sending During Network Congestion

Issues:

High gas fees
Slow confirmations
Potential transaction failures (with fees still charged)

Better: Wait for network to calm down unless transaction is urgent.

Mistake 6: Not Saving Transaction IDs

After sending:

Copy and save transaction ID (hash)
Useful for tracking
Needed for support if issues arise
Proof of sending

Especially important for:

First-time recipients
Large amounts
Business transactions

Mistake 7: Rushing Due to "Urgency"

Scammer tactics:

"Limited time offer"
"Price expiring soon"
"Send now or lose access"

Reality: Legitimate transactions don't require rushing. Urgency is a scam indicator.

If you feel rushed, stop. Take time to verify everything.

💡The 10-Minute Rule

For any transaction over $100, wait 10 minutes after preparing it. Use that time to verify address, amount, fees, and whether the transaction makes sense. This pause prevents impulsive mistakes.