Batch Transaction

A batch transaction bundles multiple separate payments into one Bitcoin transaction with multiple outputs. Instead of n transactions each with their own inputs, fee overhead, and confirmation wait, you make one transaction paying n recipients at once.

The savings are real. A transaction's bytes are dominated by inputs (script, signature, witness data), not outputs. Adding a fifth output to a transaction adds maybe 30 vbytes; sending five separate transactions costs five full transactions worth of input overhead. Exchanges processing withdrawals, custodians paying out coupons, payroll services, mining pool payouts: all classic batch-transaction users. Coinbase Exchange's batched withdrawals are estimated to have saved millions of dollars in network fees over the years.

What you give up:

• Privacy for recipients. All n recipients are visible in one transaction. Chain analysis can cluster them as "paid by the same source on the same day" much more confidently than n separate transactions would allow.
• Atomicity in operational systems. If one recipient address is invalid or one payment needs to be reversed, you can't just amend it; the whole batch already broadcast or already confirmed.
• Variance in confirmation. The whole batch confirms together. If you mis-fee the batch, all recipients wait.

For high-volume operators, the fee savings dominate. For privacy-sensitive flows (donations, payroll where individual amounts shouldn't be linkable), separate transactions remain the right call. The honest answer is "it depends on whose privacy you're optimizing."