LND Anchor Output Errors - Fix Reserve and CPFP Fee Bumping Issues

What Are LND Anchor Output Errors?

Anchor outputs are reserved UTXOs on each commitment transaction used for CPFP fee bumping. Errors arise when the anchor reserve is depleted or when LND cannot broadcast a fee bump in time.

Common Errors

• insufficient_anchor_reserve: balance too low
• anchor output sweep failed: no UTXOs available
• cannot bump fee: missing anchor UTXO
• anchor_reserve_satoshis required but unavailable

Fix: Ensure Anchor Reserve

# Check current wallet balance
lncli walletbalance

# LND requires ~10k sats per channel as anchor reserve
# Keep on-chain balance above: num_channels * 10000 sats

# Check anchor reserve requirement
lncli getinfo | grep -i anchor

Fix: Fund the On-Chain Wallet

# Get deposit address
lncli newaddress p2wkh

# Send at least 50k sats for a few channels
# Then verify
lncli walletbalance

Check Pending Anchor Sweeps

# List pending sweeps
lncli pendingsweeps

# List pending channels (force-close)
lncli pendingchannels

# Bump fee on stuck sweep
lncli wallet bumptx --txid <txid> --target_conf 3

Disable Anchor Channels (not recommended)

# In lnd.conf
[protocol]
protocol.no-anchors=true

# Note: disables anchor channels for new opens only

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