LND On-Chain Fees -- Control Sweep and Anchor Fee Rates

On-Chain Fee Settings in LND

LND uses on-chain transactions for channel opens, closes, and HTLC sweeps. High or misconfigured fees can cause delays or overpayment.

Key Config Options (lnd.conf)

[Bitcoin]
# Confirmation target for channel opens (blocks)
bitcoin.defaultchanconfs=3

# Fee rate for anchor channel sweeps (sat/vbyte)
# Set to 0 to use auto-estimation
bitcoin.anchor-fee=0

# Max fee rate for sweeper (sat/vbyte)
bitcoin.maxfee=1000

[sweeper]
# Max feerate for HTLC/commitment sweeps (sat/vbyte)
maxfeeratepervbyte=500
numtries=10
budgettofeepct=50

Check Current Fee Estimate

lncli estimatefee --target_conf 6

Bump a Stuck Transaction (CPFP)

# List unspent UTXOs
lncli wallet listunspent --min_confs 0

# Use bumpfee for stuck sweeps
lncli wallet bumpfee --outpoint <txid:vout> --sat_per_vbyte 20

Anchor Channel Fees

Anchor channels reserve 10k sats per channel for CPFP. If the anchor UTXO is spent, emergency sweeps use whatever fee is needed to confirm within deadlines.

Common Issues

- "insufficient funds" during close: anchor reserve being used, normal

- Force close confirmation stuck: use bumpfee or wait for CPFP anchor sweep

- maxfee too low: LND will refuse to sweep if fee exceeds limit — raise it during high-fee periods