Understand the building blocks: Bitcoin addresses, formats, and checksums

Before scanning or sharing anything, it helps to know what you are looking at. A Bitcoin address is a destination identifier. Modern wallets typically show one of several formats. Each format carries a built-in checksum that helps catch typos, but no checksum can protect you if you paste a valid address that belongs to someone else. That is why verification habits matter.

Common address formats you will see in 2025

• Legacy (P2PKH): begins with 1. Example pattern: 1ABC.... Older, widely compatible.
• P2SH: begins with 3. Often used for multisig or wrapped SegWit. Example pattern: 3DEF....
• SegWit bech32: begins with bc1q. Lower fees and fewer errors due to all lowercase.
• Taproot bech32m: begins with bc1p. Newer features, increasingly common across wallets.

What checksums do and do not do

Checksums help your wallet detect accidental character flips or truncation. If you mistype part of a valid address, many wallets will refuse to send. This is useful, but it does not protect against the wrong valid address. A clipboard hijacker, for example, can substitute a different valid address. Your wallet will accept it, and your Bitcoin will be gone. Always combine checksum protection with human verification steps.

Avoid network confusion

Never send Bitcoin to an address for a different coin or a different network. Some address formats across other chains can look familiar to newcomers. Confirm that the address begins with a recognized Bitcoin mainnet prefix like bc1q, bc1p, 1, or 3, and confirm the wallet explicitly shows Bitcoin mainnet. If a friend sends you a different format and insists it is correct, pause and independently confirm with them in a second channel before proceeding.

QR codes, BIP21 invoices, and why details matter

Most people now scan rather than type. A Bitcoin QR code typically encodes a BIP21 URI that can include the address, amount, label, and a short message. Example: bitcoin:bc1qexample...?...amount=0.015&label=Invoice%20123. Not every wallet respects all fields, so always verify what your app populated before you hit send.

Static QR codes versus single-use invoices

Static QR codes never change. They are handy for a tip jar or a poster near a cafe register. The risk is address reuse, which can reduce privacy. Single-use invoices are safer for most transactions because they generate a fresh address each time. Many point-of-sale systems and non-custodial wallets can do this quickly. If you are receiving significant amounts, prefer single-use invoices.

Printing and display best practices

• Use high contrast and adequate size. A small, low-resolution QR code under glass is hard to scan.
• Leave a quiet zone around the code. Do not place text or logos right against the edges.
• Test with multiple phones before you publish a poster or checkout placard.
• If you are in a storefront, place the QR so customers cannot accidentally scan a reflection or a competing code on a nearby sign.

Onchain versus Lightning in one QR

Some wallets support multiple payment methods in one display, such as showing a Bitcoin onchain address alongside a Lightning invoice. If your customer or donor scans the wrong one, they may pay a different network than you intended. Label your options clearly and train staff to guide users. If you only want onchain, configure your wallet to present only the Bitcoin address.

The sender’s safety checklist

Run through this quick checklist every time you send. It is easy to memorize and it dramatically reduces risk.

• Confirm you are on Bitcoin mainnet in your wallet settings.
• Verify the prefix: bc1q, bc1p, 1, or 3. If it is different, stop and investigate.
• Compare the first 6 and last 6 characters of the address with a second device or with the original source. Speak them aloud to yourself or a colleague.
• Use a small test send for large or first-time recipients. Wait for at least one confirmation before sending the balance.
• Check the amount and unit. Most wallets default to BTC, but if you type a CAD value, confirm the conversion back to BTC looks right.
• Review the network fee and ensure the fee is appropriate for your urgency. Enable Replace by Fee if your wallet supports it for flexibility.
• If you use a hardware wallet, confirm the full address and amount on the device screen, not just on the computer.
• Beware of clipboard manipulation. After pasting the address, re-check the first and last characters before sending.
• Keep your device focused during the send. Do not multitask or switch apps until the transaction is broadcast.
• Save the transaction ID inside your wallet notes or export it to your records for reconciliation and tax purposes.

The receiver’s playbook: safer requests and confirmations

If you frequently receive Bitcoin, set up a smooth and repeatable process. This reduces confusion and helps your auditors or accountant later.

Generate fresh addresses

Use a wallet that supports automatic address rotation so every payment goes to a new address. This protects your privacy and makes bookkeeping easier. For recurring clients, label each invoice with a reference and amount in your records, even if your wallet does not display labels to the sender.

Set clear confirmation policies

Let customers know how many confirmations you require before you consider funds final. For small retail payments, some merchants accept zero confirmation risk. For higher values, one to three confirmations is common. For very large or business critical transfers, many receivers wait for additional confirmations. Document your policy so staff do not guess at the register.

Avoid address reuse on public pages

If you publish a donation QR on your website or a poster, periodically update it or implement a process that generates a unique address per donor. Static addresses can leak financial information over time because anyone can see funds arriving. Even if privacy is not a concern, rotating addresses helps you match payments to people.

Defend against malware and human error

Security is not only about strong devices. It is also about predictable habits. Combine technology with a routine that makes mistakes unlikely.

Clipboard hijackers and overlays

A common threat replaces copied addresses with an attacker’s address. The best defense is to confirm the first and last characters after you paste. On computers, use a hardware wallet and verify the address on the device screen. On phones, avoid installing random QR scanner apps. Use your wallet’s built-in scanner and review the pasted results before sending.

Camera hygiene

Allow camera permission only for your wallet and for apps you trust. If a malicious app can draw over your screen, it might display a fake QR preview. Keep your operating system updated and avoid sideloading software. In a public place, block glare and reflections that can interfere with scanning and cause rushed mistakes.

Social engineering and face-to-face risks

If you meet a stranger to complete a Bitcoin deal, stick to public, well-lit places and avoid making on-device changes under pressure. Never accept to scan a code from a stranger’s phone without confirming the details on your own wallet screen. If someone asks you to prove a payment by sending a small amount first and promises to send it back, decline. Use a trusted marketplace or an escrow workflow instead of ad hoc peer deals.

A quick pause to verify the first and last six characters would have stopped most sending mistakes I have seen over the years. Make it a habit and you will never regret the extra five seconds.

Canadian context: Interac habits, banking, and compliance

Canadians bring strong e-transfer habits to Bitcoin. That is useful for speed, but it can create false assumptions about reversibility. Keep these points in mind.

Interac e-Transfer is not Bitcoin

Interac e-Transfer can sometimes be canceled or recalled before it is deposited. Bitcoin settlements are final once confirmed. If you receive Bitcoin and then send goods or cash immediately, there is no recall option. Protect yourself with clear confirmation policies and do not let e-transfer expectations shape your Bitcoin risk decisions.

Banks and crypto transactions

Canadian banks vary in how they treat cryptocurrency purchases and withdrawals. Plan significant moves during business hours so you can reach support if needed. When withdrawing to self-custody, send a small test transaction first and confirm it arrived. Keep screenshots of your wallet’s receive page and your bank statements for reconciliation.

Recordkeeping and compliance for businesses

If you accept Bitcoin as a business in Canada, maintain clear records that link invoices to addresses and amounts. Keep customer communications, payment references, and timestamps. Depending on your business model, you may have obligations under Canadian regulations that require robust transaction records. This article is for education, not legal advice. When in doubt, speak with a qualified professional.

Practical wallet configurations that help prevent errors

Most modern wallets include settings that improve address safety. Turn these on once and you will make future mistakes less likely.

Prefer bech32 or Taproot addresses

Set your default receive address type to bech32 or Taproot. These formats are compact, case consistent, and widely supported across wallets and exchanges in 2025. They also reduce fees for many transactions. If a counterparty cannot send to bc1 addresses, consider whether you want to proceed. Downgrading for compatibility can be acceptable, but confirm carefully.

Label every payment and use BIP21 fields

When you generate a request, add a label such as an invoice number, customer name, or a purpose. Even if the sender’s wallet ignores it, your own wallet’s records will be more useful later. Enable address expiration if available so old QR codes cannot be reused by mistake.

Hardware wallet plus mobile scanning

A strong flow for Canadians who self-custody is to store keys on a hardware wallet and use a mobile app in watch-only mode for scanning requests. You can verify addresses on the hardware device screen and then broadcast from the phone. This keeps keys offline while preserving convenience.

Troubleshooting common address and QR mistakes

Even with good habits, you may hit a snag. Here is how to handle common issues without panic.

The QR will not scan

• Increase screen brightness and reduce glare. Tilt the phone until the code fills the frame.
• Ask the receiver to enlarge the code. Small or low-resolution codes often fail.
• If printed, ensure the code has a quiet zone and is not creased or smudged.
• As a backup, copy the address text, but verify the first and last characters after pasting.

Wrong amount due to decimal mixups

Canada uses a period as the decimal separator. If you are used to commas from another locale, double check the displayed amount after scanning. Many wallets let you enter the amount in CAD and will convert to BTC automatically. Always verify the BTC figure before sending.

Sent to the wrong valid address

If you already broadcast a transaction to a valid address that is not the intended recipient, there is no built-in recall. Contact your wallet provider for logs, document everything, and if you know the receiver, reach out immediately. For custody mistakes on an exchange, open a support ticket with precise timestamps and transaction IDs. For self-custody errors, focus on prevention for the future. This is why test sends help.

Confusion between onchain and Lightning

If you meant to pay onchain but scanned a Lightning invoice, the funds will not arrive in the receiver’s onchain wallet. Cancel and ask for the correct invoice type. Receivers should label the method clearly and staff should know how to switch views on the point-of-sale device.

Two quick stories that highlight best practices

If a payment is mission critical, verify on two independent screens and consider a test send. It transforms stress into routine.

A simple, repeatable process for Canadians

Build a standard operating procedure for yourself or your team. Print it, share it, and practice it. Here is a concise template you can adapt.

• Use a reputable non-custodial wallet and keep it updated. Prefer a hardware wallet for long-term storage.
• Set default receive type to bech32 or Taproot. Enable address rotation and invoice labels.
• For requests, generate a single-use invoice with a clear label and amount. If you must use a static QR, refresh it regularly.
• When sending, verify prefix and match first six and last six characters with the original source. Confirm on the device screen for hardware wallets.
• Use test sends for large transfers. Wait for your chosen number of confirmations before releasing goods or additional funds.
• Keep organized records for reconciliation, tax calculations, and audits. Capture invoice references, transaction IDs, and timestamps.

Frequently asked questions