Cancel blocked units

Cancel units from a holder after removing the holder from a B20 sender allowlist.

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.

Real-world asset (RWA) tokenization is one of many use cases for the B20 Asset standard. The examples on this page use a stock token for illustration; the same flows apply to other asset types.

Tokenized securities examples shown for illustration. Base is a general-purpose blockchain; issuance and compliance are the responsibility of the issuer under applicable law.

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

TypeScript

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] });
}

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