Quick answer
Yes. Bitcoin is designed to be fractional. One bitcoin equals 100,000,000 satoshis, and Bitcoin transactions are constructed and recorded in satoshis, not whole coins. That means you can buy or send less than 1 BTC—in fact, far less.
Bitcoin units you’ll actually use
- 1 BTC = 100,000,000 satoshis (often shortened to “sats”).
- Wallets and explorers increasingly display values in sats because the chain itself accounts in sats.
For context, community documentation also lists intermediate units like mBTC (one-thousandth) and “bits,” but sats are the standard fine unit today.
Can you buy a fraction of a bitcoin on exchanges?
Yes. Major platforms explicitly allow fractional purchases; the minimum purchase is a platform rule, not a network rule. Coinbase notes you don’t need to buy a whole coin, and also explains that minimum purchase amounts vary by crypto and payment method. Binance sets minimum “notional” sizes per trading pair (for example, 5 USDT in many spot markets).
Withdrawals also have platform-specific minimums. For example, Coinbase Exchange shows a BTC minimum withdrawal field in its help docs, and Kraken publishes a table of crypto withdrawal minimums and fees. These are custodian policies, not protocol limits.
What’s the smallest amount you can send on-chain?
On-chain, the protocol supports tiny values down to 1 satoshi, but practical network policy and fees enforce a floor called the dust limit. Outputs smaller than the dust limit are typically refused by nodes and miners because they would cost more to spend than they’re worth (“uneconomical outputs”).
- As a rule of thumb, an old-style P2PKH output below ~546 sats is considered dust; for modern native SegWit (P2WPKH) it’s ~294 sats; Taproot (P2TR) is ~330 sats. Exact thresholds depend on the node’s fee policy and output type.
- Fees are paid per vbyte of transaction data, so very small payments can become impractical during busy periods even if they’re above the dust line.
In short: you can send a small fraction, but try to keep the output above the dust limit and budget a fee appropriate for current blockspace demand.
How small can you go off-chain (Lightning Network)?
The Lightning Network is built for fast, tiny payments. Internally it uses millisatoshis (msat), which are thousandths of a satoshi, so implementations can account for amounts smaller than one sat. Invoices follow the Lightning specifications (“BOLTs”). Wallet UX often rounds to whole sats for user payments.
Fees and practical limits to keep in mind
- On-chain fees are based on size (sat/vB), not the BTC amount. High-demand periods raise fees, which can make tiny on-chain sends uneconomical.
- Many custodians set minimum buy/sell/withdraw amounts; check your platform’s limits page.
- For frequent micro-purchases or tipping, Lightning can avoid large on-chain fees; some exchanges and wallets now support Lightning sends/withdraws.
Examples of “smallest” amounts in the real world
- Buying a fraction: Exchanges let you purchase tiny amounts; Binance spot commonly enforces a ~5 USDT notional minimum per order, while Coinbase confirms you can buy less than 1 BTC but the minimum varies by method.
- Withdrawing from custodians: Help pages show explicit BTC minimum withdrawal amounts (e.g., Coinbase Exchange displays a min_withdrawal_amount field; Kraken lists asset-specific minimums).
- Sending on-chain: Keep outputs above dust (≈294–546+ sats depending on address type) and include a suitable sat/vB fee so your transaction relays and confirms.
- Sending off-chain: Lightning uses msats under the hood and is built for micropayments; implementations follow the BOLT specs.
FAQs
Can I send 0.00000001 BTC (1 satoshi) on-chain?
The protocol can represent 1 sat, but nodes enforce dust-limit policy. A 1-sat output is below common dust thresholds and will usually be rejected or require nonstandard handling. Aim above dust for reliable relay and confirmation.
Why did my wallet block a “tiny” send?
Most wallets follow node policies to prevent creating dust or uneconomical outputs, and they estimate fees per vbyte to help your transaction clear.
Is Lightning the best way to send pennies’ worth?
For frequent or very small payments, yes—Lightning is purpose-built for small, instant transfers and accounts in millisatoshis. Your wallet or exchange must support it.
How to buy and send less than 1 BTC, step by step
Buying a small amount
- Choose a reputable platform and check its minimum order size. Many allow buys well under $10, but exact thresholds vary by platform and pair.
- Fund your account and place a market or limit order for your chosen amount.
Sending a small amount on-chain
- Ask the recipient for their address type (bc1… SegWit/Taproot preferred).
- Enter an amount comfortably above your address type’s dust limit and choose a fee rate that suits your urgency.
Sending a small amount via Lightning
- Use a Lightning-enabled wallet or exchange.
- Scan the Lightning invoice and pay; Lightning uses msats internally to support micropayments.
