Explain a TRON Bandwidth burn when two quotas look sufficient

An ordinary transfer can burn TRX even when the sum of free and staked Bandwidth exceeds its size. Each candidate source must cover the entire charge on that path.

Compare the charge to each available source

Read NetLimit and NetUsed from wallet/getaccountresource for the sender, then freeNetLimit and freeNetUsed. Compute each remaining quota separately. The example uses an ordinary transfer with an observed charge of 260 Bandwidth and two remaining sources.

staked_remaining = 180
free_remaining = 220
chargeable_bytes = 260
assert max(staked_remaining, free_remaining) < chargeable_bytes

Reconcile the full fallback cost

Neither 180 nor 220 covers 260, so adding them to produce 400 would predict the wrong outcome. Inspect the confirmed transaction receipt’s net_fee and the network’s active Bandwidth price at execution. Account creation and some token transfers have their own resource rules. Also capture the observation time because quotas recover between reads.

Sources