Coinbase maturity

Why rewards have their own delay

The miner transaction is part of its containing block. If that block leaves the accepted chain, its reward is no longer part of that chain either. Delaying spends reduces the immediate consequences of spending rewards from a branch that may be replaced.

This is separate from the spendable-age rule applied to ordinary received outputs. Do not use the ordinary payment waiting period to estimate when a solo-mining reward or direct P2Pool payout can be spent.

References: Monero source: cryptonote_config.h · Monero source: cryptonote_core/blockchain.cpp

Reading a wallet balance

A wallet can recognize a reward and include it in total balance while excluding it from unlocked balance. That difference does not mean a pool is withholding a transaction already recorded on the chain.

Check the transaction type, containing height and current wallet synchronization before treating the delay as a fault. The network rule uses heights. Wallet interfaces may describe it using confirmations, blocks remaining or an estimated time.

References: Monero source: cryptonote_config.h · Monero source: cryptonote_core/blockchain.cpp · Monero source: wallet/wallet2.cpp

Example

A reward created at height H has an unlock height of H + 60. A wallet can show the incoming reward before that height while keeping it outside the spendable balance.

References: Monero source: cryptonote_config.h · Monero source: cryptonote_core/blockchain.cpp

Limits and cautions

Sixty target block intervals are roughly two hours, not an appointment with a clock. Blocks arrive irregularly, reorganizations can change the relevant history, and a wallet must have synchronized before its display is useful.

References: Monero source: cryptonote_config.h · Monero source: cryptonote_core/blockchain.cpp