SIMD-0085: Additional Fee Collector Constraints

proposals/0085-additional-fee-collector-constraints.md

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+---
+simd: "0085"
+title: Additional Fee Collector Constraints
+authors:
+  - Justin Starry
+category: Standard
+type: Core
+status: Draft
+created: 2023-11-05
+feature: https://github.com/solana-labs/solana/issues/33888
+---
+
+## Summary
+
+Burns fees if they would otherwise be collected into an account that violates
+one of the following constraints:
+
+1. Must be a system owned account
+2. Must be rent-exempt
+
+This applies to both transaction fees and rent fees. Note that the "rent-exempt"
+constraint was already added for rent fee collection in
+[Feature 30151](https://github.com/solana-labs/solana/issues/30151).
+
+## Motivation
+
+1. Since fee collection occurs outside of the runtime, it's generally a good
+   idea to reduce the number of account modification edge cases.
+2. Prevent new rent paying accounts from being created
+
+## Alternatives Considered
+
+NA
+
+## New Terminology
+
+NA
+
+## Detailed Design
+
+At the end of a block, validators MUST NOT distribute fees to accounts that are
+not system owned and/or rent-exempt. Instead, they MUST burn the fees by not
+distributing them to anyone.
+
+## Impact
+
+New and existing validators must ensure that their fee collection account is
+rent-exempt and owned by the system program in order to receive fees. Since the
+Solana Labs validator implementation currently requires the fee collector
+account to be same account as the fee payer for vote transactions, this is
+unlikely to impact any validators unless they run a custom implementation.
+
+Validators will still be able to collect fees into durable nonce accounts if
+they wish. If a validator does not wish to use a hot wallet to have custody
+over collected fees, they may use durable nonce accounts which have a
+configurable authority address.
+
+## Security Considerations
+
+Note that durable nonce accounts are system owned and rent exempt and can
+therefore continue to be used for fee collection.