---
title: "Propose Block Trade"
method: POST
path: "/communications/block-trade-proposals"
tags: ["communications"]
---

# Propose Block Trade

`POST /communications/block-trade-proposals`

Endpoint for creating a block trade proposal.

## Request body

- ProposeBlockTradeRequest
  - `buyer_user_id` string, required — User ID of the buyer
  - `buyer_subtrader_id` string — Subtrader ID of the buyer. Provide either this or buyer_subaccount, not both.
  - `buyer_subaccount` integer — User-managed subaccount number of the buyer (0 for primary, 1-63 for numbered subaccounts). Provide either this or buyer_subtrader_id, not both.
  - `seller_user_id` string, required — User ID of the seller
  - `seller_subtrader_id` string — Subtrader ID of the seller. Provide either this or seller_subaccount, not both.
  - `seller_subaccount` integer — User-managed subaccount number of the seller (0 for primary, 1-63 for numbered subaccounts). Provide either this or seller_subtrader_id, not both.
  - `market_ticker` string, required — The ticker of the market for this block trade
  - `price_centi_cents` integer, required — Price in centi-cents
  - `centicount` integer, required — Number of contracts in centicounts
  - `maker_side` 'yes' | 'no', required — The maker side of the trade
  - `expiration_ts` string, date-time, required — Expiration time of the proposal

## Response `201`

Block trade proposal created successfully

- ProposeBlockTradeResponse
  - `block_trade_proposal_id` string, required — The ID of the newly created block trade proposal

## Other responses

- `400` — Bad request - invalid input
- `401` — Unauthorized - authentication required
- `403` — Forbidden - insufficient permissions
- `500` — Internal server error

---

[API](https://skmtc.net/kalshi/apis/kalshi-trade-api-manual-endpoints.md) · [All operations](https://skmtc.net/kalshi/apis/kalshi-trade-api-manual-endpoints/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/kalshi/kalshi-trade-api-manual-endpoints/revisions/6aec27d55fba/schema)