Fee subsidy transition

Bitcoin's security budget is designed to transition from new issuance to transaction fees. The subsidy declines geometrically and truncates to zero around the year 2140 (the last sat of subsidy is projected decades earlier than the final zero-subsidy halving boundary), after which miner revenue is fees only. This transition is described in the whitepaper itself (Section 6), not a later improvisation.

Nuance: Whether fee revenue alone will sustain adequate security is a genuinely open economic question — it belongs in claims/, not here. The fact is the mechanism: subsidy ends, fees remain. Note also that fees already fluctuate between a small fraction and (occasionally) a majority of block rewards during demand spikes; there is no fixed "fee era" start date.

Common misstatements:

• "Bitcoin stops working in 2140." — Mining and transaction processing continue; only new issuance stops.
• "The last bitcoin will be mined in 2140, then miners are unpaid." — Fees continue as compensation; the whitepaper describes exactly this transition.
• "Fees must replace the subsidy at the next halving." — The transition is gradual over ~a century, not a cliff.