New issuance model for Polkadot

[ggwpez]

OpenGov approved a new issuance model for the DOT token in ref 1710. The current one is ref 1139.
The change will happen on March 14, 2026. Until then, everything stays the same.

Changes

Capped supply

The DOT token supply is currently uncapped and will be capped to 2.1 Billion DOT (2,100,000,000 DOT).

Issuance Rate Reduction

The current model issues a fixed amount of ~120 Million DOT per year (328,797 per day).

The new model issues 13.14% of the remaining tokens every year. The issuance rate is updated every two years.
This works out to ~56 Million DOT per year (152,271 per day) in the first two years (March 14, 2026 - March 14, 2028). Note that the exact values are estimates and will only be known after the Polkadot runtime fixes them on 14th Match 2026.

TODO:

• Merge code Implement 'Hard Pressure' Issuance Model #898
• Deploy on-chain
• Possibly adjust start block number to be close to Match 14, 2026 in case of clock drift
• Remove pre-march14 inflation code post march14
• Replace March2026TI storage value with hardcoded value once set

[PolkadotDom]

I'd think let's add

• Remove pre-march14 inflation code post march14
• Replace March2026TI storage value with hardcoded value once set

as well