Cancel Blocked Shares - Base Documentation

Cancel shares from a holder who is already denied by the token’s transfer-sender policy. Removing the holder from an allowlist freezes outgoing transfers; burnBlocked then burns the specified shares and reduces total supply.

Demo

New to B20? See the B20 Token Standard for the concepts and a full launch walkthrough. These samples target base-std@v1.0.0, viem@2.55.11, and Base Foundry v1.1.1.

Cancel and verify blocked shares

import { parseUnits, type Address } from "viem";
import { publicClient } from "../../shared/clients.js";
import { b20Abi } from "../abi.js";
import { sendContract } from "../write.js";

export async function cancelBlockedShares(token: Address, holder: Address) {
  const amount = parseUnits("100", 6);
  await sendContract({ address: token, abi: b20Abi, functionName: "burnBlocked", args: [holder, amount] });
  return publicClient.readContract({ address: token, abi: b20Abi, functionName: "balanceOf", args: [holder] });
}

    function cancelBlockedShares(address token, address holder) public {
        IB20(token).burnBlocked(holder, 100e6);
    }

base-cast send "$TOKEN_ADDRESS" "burnBlocked(address,uint256)" "$BLOCKED_HOLDER" 100000000 \
  --rpc-url "$RPC_URL" --private-key "$PRIVATE_KEY"
base-cast call "$TOKEN_ADDRESS" "balanceOf(address)(uint256)" "$BLOCKED_HOLDER" --rpc-url "$RPC_URL"

See the complete verified B20 examples for imports, client construction, and runnable projects.

The holder balance and total supply each fall by 100 EXM.

burnBlocked destroys shares; it does not move them to the issuer. Block the holder under TRANSFER_SENDER_POLICY first.

See also

Restrict eligible holders · Issue shares
Burn and Policy integration in the B20 standard