Send & Pay Safely — Networks, QR, Fees, Confirmations, Test Tx
Select the correct network, verify address/memo, account for platform fees, send a tiny test transaction, then the final amount exactly as on the invoice. Learn confirmations, timing, refund finality, and how to record a payment.
4.1Networks and address rules (critical)
Critical: Network Mismatch = Permanent Loss
Sending crypto to the wrong network address can result in irreversible loss of funds.
- Match coin + network on both sides (e.g., USDT TRC20 on TRON; USDT ERC20 on Ethereum; USDC SOL on Solana). Wrong network can lead to permanent loss.
- Some deposits require memo/tag/ID (e.g., XRP, XLM, BNB, some exchange addresses). Always include when asked.
- Prefer scanning QR from the invoice; if copying, verify first/last characters of the address; beware "address poisoning" (fake look-alikes in recent history).
- If unsure — stop. Ask the payee or use their official help.
Common coin/network combinations
| Coin | Networks |
|---|---|
| USDT | TRC20 (TRON), ERC20 (Ethereum), BEP20 (BSC), SOL (Solana) |
| BTC | Bitcoin, Lightning Network |
| ETH | Ethereum, Arbitrum, Optimism, Base |
| USDC | ERC20 (Ethereum), SOL (Solana), TRC20 (TRON), Arbitrum |
Exchanges often offer multiple networks for one coin — choose the one the payee explicitly supports.
4.2Exact amount & platform fee handling (exchange vs wallet)
Invoices often specify an exact crypto amount (e.g., 100.00 USDT). Sending less (even by fees) can mark payment "underpaid."
Self-custody wallet
Fee is paid on top by your wallet (you still send the full amount to the recipient).
Exchange withdrawal
Many exchanges deduct a fixed withdrawal fee from the sent amount, unless they support a "net" option (send exact amount; fee charged separately).
Amount Calculator
Guidance
Send 100.00; wallet adds network fee separately.
Some exchanges show "You will receive" on confirmation. Confirm this equals the invoice amount before proceeding.
4.3Fees and timing: mempool, congestion, exchange withdrawals
- Bitcoin/Ethereum: variable fees depending on mempool and congestion; consider higher fee tiers for speed if the invoice expires soon.
- TRON/Solana: typically low fees and fast confirmations; still confirm the exact network required by payee.
- Exchange withdrawal fees: fixed per network/coin; check the fee before confirming; account for "net vs gross" as above.
- Confirmations: Some processors require N confirmations before marking payment "paid." Check the invoice or merchant policy.
- Expiry: Some invoices expire; pay within the timeframe or create a new one.
Network comparison (typical values)
| Network | Fee | Time | Confirmations |
|---|---|---|---|
| Bitcoin | $1–$10+ | 10–60 min | 1–6 |
| Ethereum | $1–$20+ | 15 sec–5 min | 12–32 |
| TRON (TRC20) | ~$1 | ~3 sec | 19 |
| Solana | <$0.01 | ~0.4 sec | 32 |
| Lightning | <$0.01 | Instant | N/A |
4.4QR and address entry: safer input methods
- Prefer scanning QR from the invoice (less error-prone).
- If copying, paste into wallet/exchange, then manually check first/last characters and network.
- For memo/tag/ID: paste from invoice; losing it may prevent crediting funds to recipient account (especially exchanges).
- Avoid copy/paste from transaction history (address poisoning); copy only from the live invoice or verified address book.
Address format examples
| Type | Pattern | Length |
|---|---|---|
| Bitcoin | bc1q... or 1... or 3... | 26–62 chars |
| Ethereum/ERC20 | 0x... | 42 chars |
| TRON (TRC20) | T... | 34 chars |
| Solana | Base58 string | 32–44 chars |
4.5Test transaction: tiny amount first
Send a tiny amount (e.g., $1–$5 equivalent) first to the same address & network. Wait for required confirmations; verify recipient/system marks it as received. Then send the remaining amount (gross vs net as per Section 4.2).
Test Transaction Instructions
Send 1 USDT TRC20 to [address]; wait 19 confirmations; then proceed with final payment.
4.6Refunds and reversals (finality)
Remember: No chargebacks
Unlike credit cards, crypto payments cannot be reversed by you. Triple-check everything before confirming.
- Crypto transactions are final; only the recipient can refund you.
- Under/overpayments: Payment processors often mark "underpaid/overpaid" and may provide instructions; otherwise contact support with transaction ID.
- Wrong network or missing memo/tag (to exchanges) may be unrecoverable or require complex support with low success rate. Always verify before sending.
- Keep transaction hash/ID, amount, and timestamp as proof.
4.7Practice: test to self + mock invoice flow
Practice steps
From your wallet, send a tiny test to another of your addresses (own second wallet/exchange deposit).
Record transaction hash, network, fee, number of confirmations at receipt.
Prepare a mock invoice flow: Fill recipient address/network/memo (fake or your own), set an exact amount, set expiry.
Run through "net vs gross" decision logic; draft steps you'd take on an exchange and in a self-custody wallet.
Payment Record (deliverable)
Your Payment Record:
Payment Record Recipient (name/label): ___ Network: ___ Invoice amount: ___ Fee mode: ___ Test tx hash: ___ Test tx date/time: ___ Confirmations observed: ___ Final tx plan (amount handling, fee estimate, expiry): ___
4.8Deliverable: One-page payment checklist
4.9Mini-Quiz
Mini-Quiz
Test your understanding with 3 questions. Pass with 2/3 correct.
Educational content only. Not financial advice. Crypto involves risk of capital loss. Verify network, memo/tag, and fees; use a tiny test first; keep transaction records.