ZIP: 2009
Title: Reduce Marginal Fee to 1000 Zatoshis and Raise the Weight Ratio Cap to 10
Owners: Mark Henderson <[email protected]>
Status: Draft
Category: Standards / Wallet
Updates: ZIP 317
Created: 2026-04-06
License: MIT
Discussions-To: <https://github.com/zcash/zips/issues/1388>
Pull-Request: <https://github.com/zcash/zips/pull/1352>

Terminology

The key words “MUST”, and “SHOULD” in this document are to be interpreted as described in BCP 14 ¹ when, and only when, they appear in all capitals.

Fee terminology is as defined in ZIP 317 ²; “zatoshi” is as defined in the Zcash protocol specification. ³

Abstract

This ZIP cuts ZIP 317’s ² marginal_fee from 5,000 to 1,000 zatoshis per logical action, so the minimum conventional fee drops from 10,000 to 2,000 zatoshis. It also raises weight_ratio_cap in ZIP 317’s block template algorithm from 4 to 10, so that the fee cut does not narrow the range as sharply. Nothing else in ZIP 317 changes.

Motivation

ZIP 317’s fee was set in late 2022, when ZEC was about $30 and the minimum fee of 10,000 zatoshis cost about a third of a cent in USD. The fee is fixed in zatoshis, so when the price went up, so did the fee. At $800 (the price on 2026–08–29) the minimum fee costs 8 cents.

Cutting marginal_fee to 1,000 brings the minimum fee to 2,000 zatoshis, about 1.6 cents. Even after a 5x cut, it is still 5x more than it was when ZEC was $30. It only gets cheaper than the 2022 fee if ZEC falls below $150.

Additionally, weight_ratio_cap is a multiple of the conventional fee, so cutting marginal_fee shrinks the range of inclusion-influencing fees from 10,000 - 40,000 zatoshis to 2,000 - 8,000. Raising weight_ratio_cap to 10 widens that range to 2,000 - 20,000, still below the today’s maximum. It also keeps transactions from wallets that have not yet updated, which pay 5x the new conventional fee, from being clamped at the cap.

Privacy Implications

Privacy: If wallets switch to the new fee at different times, the fee reveals which wallet software made the transaction. To keep that window short, wallets SHOULD switch at the activation height given under Deployment, not when the release ships.

Specification

Changes to ZIP 317

In the parameter table of the Fee calculation section of ZIP 317 ², the entry

marginal_fee | 5000 | zatoshis per logical action (as defined below)

is replaced with

marginal_fee | 1000 | zatoshis per logical action (as defined below)

No other entry in the table changes.

If ZIP 235 ⁴ activates, the fraction removed from circulation is unchanged: of a 2,000-zatoshi fee, 1,200 zatoshis are removed and 800 go to the miner.

Change to weight_ratio_cap

In the section Recommended algorithm for block template construction of ZIP 317, replace the constant definition weight_ratio_cap = 4 with weight_ratio_cap = 10, and update the rationale as follows:

The rationale for choosing weight_ratio_cap = 10 is as a compromise between not allowing any prioritization of transactions relative to those that pay the conventional fee, and allowing arbitrary prioritization based on ability to pay. Because the cap is a multiple of the conventional fee, the fee at which a transaction’s weight ratio saturates falls with marginal_fee. A cap of 10 at marginal_fee = 1000 places that point below where it was at weight_ratio_cap = 4 and marginal_fee = 5000.

Interaction with the getstandardfee RPC endpoint

zebrad’s getstandardfee RPC endpoint reports the ZIP 317 marginal_fee. Implementations providing this or an equivalent endpoint MUST report 1,000 zatoshis per logical action from the activation height given in the Deployment section.

Rationale

Why a marginal_fee of 1,000. A 5x cut still leaves the fee 5x above its 2022 dollar cost as of 2026–08–29.

Why a weight_ratio_cap of 10. This maintains the rationale in ZIP 317, section “Rationale for block template construction algorithm”, of limiting the ability of an adversary to gain a significant advantage over other users by paying more than the conventional fee.

Precedent. ZIP 313 ⁵ reduced the conventional fee in 2020 the same way: a wallet convention, no network upgrade.

Deployment

Node implementations MUST ship the new relay policy before wallets adopt the new fee. block_unpaid_action_limit is 0 in both zebra and zakura and is not operator-configurable, so an un-upgraded node will not relay a 2,000-zatoshi transaction at all, since it counts 2 unpaid actions under the old parameters.

Wallets SHOULD adopt marginal_fee = 1000 at Mainnet block height 3590000, expected in mid December 2026. This is past the end-of-service halt of both zebra v6.3.0 (height 3564960) and zakura v1.3.1 (height 3501339), by which point operators still running MUST have moved to a release carrying the new policy.

The weight_ratio_cap change affects block producers only and has no wallet dependency, so the two parameter changes can be adopted in either order.

References