Game concept
Treasury Budgeting
The game also links it as Treasury Budget.
From the game's encyclopedia
A system responsible for distributing central funds to specific Vassals and sub-vassals at specific allocation rates.
When a budget is enacted, a per-vassal Budget Base Rate is calculated for each Budget Category based on the available Budget Capacity.
The calculated base rate will not be changed until a new budget is enacted in the future! So if you get more recipients, your budget costs will rise.
The game's text for patch 1.20.1.2. Words in blue are entries of the encyclopedia: hover one to read it, as in the game.
Treasury Budgeting is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "A system responsible for distributing central funds to specific Vassals and sub-vassals at specific allocation rates." It covers Budget Capacity, Budget Base Rate, Budget Category, Budget Category Trend, Unallocated Treasury Budget and 1 more. The game also links it as Treasury Budget. Patch 1.20.1.2, from game/common/game_concepts/tgp_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/tgp_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.