What are smart contracts on blockchain?
Smart contracts are digital contracts stored on a blockchain that are automatically executed when predetermined terms and conditions are met
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Smart contracts defined

Smart contracts are simply programs stored on a blockchain that run when predetermined conditions are met. They typically are used to automate the execution of an agreement so that all participants can be immediately certain of the outcome, without any intermediary’s involvement or time loss. They can also automate a workflow, triggering the next action when conditions are met.

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How smart contracts work

Smart contracts work by following simple “if/when…then…” statements that are written into code on a blockchain. A network of computers executes the actions  when predetermined conditions have been met and verified. These actions could include releasing funds to the appropriate parties, registering a vehicle, sending notifications, or issuing a ticket. The blockchain is then updated when the transaction is completed. That means the transaction cannot be changed, and only parties who have been granted permission can see the results.

Within a smart contract, there can be as many stipulations as needed to satisfy the participants that the task will be completed satisfactorily. To establish the terms, participants must determine how transactions and their data are represented on the blockchain, agree on the “if/when...then…” rules that govern those transactions, explore all possible exceptions, and define a framework for resolving disputes.

Then the smart contract can be programmed by a developer – although increasingly, organizations that use blockchain for business provide templates, web interfaces, and other online tools to simplify structuring smart contracts.

What is blockchain for business?
Benefits of smart contracts
Speed, efficiency and accuracy

Once a condition is met, the contract is executed immediately. Because smart contracts are digital and automated, there’s no paperwork to process and no time spent reconciling errors that often result from manually filling in documents.

Trust and transparency

Because there’s no third party involved, and because encrypted records of transactions are shared across participants, there’s no need to question whether information has been altered for personal benefit.


Blockchain transaction records are encrypted, which makes them very hard to hack. Moreover, because each record is connected to the previous and subsequent records on a distributed ledger, hackers would have to alter the entire chain to change a single record.


Smart contracts remove the need for intermediaries to handle transactions and, by extension, their associated time delays and fees.

Applications of smart contracts

Explore how businesses benefit from smart contracts in active blockchain solutions

Safeguarding the efficacy of medications

Sonoco and IBM are working to reduce issues in the transport of lifesaving medications by increasing supply chain transparency. Powered by IBM Blockchain Transparent Supply, Pharma Portal is a blockchain-based platform that tracks temperature-controlled pharmaceuticals through the supply chain to provide trusted, reliable and accurate data across multiple parties.

Explore IBM Blockchain Transparent Supply
Increasing trust in retailer-supplier relationships

The Home Depot uses smart contracts on blockchain to quickly resolve disputes with vendors. Through real-time communication and increased visibility into the supply chain, they are building stronger relationships with suppliers, resulting in more time for critical work and innovation.

Learn how The Home Depot builds trust
Making international trade faster and more efficient

By joining we.trade, the trade finance network convened by IBM Blockchain, businesses are creating an ecosystem of trust for global trade. As a blockchain-based platform, we.trade uses standardized rules and simplified trading options to reduce friction and risk while easing the trading process and expanding trade opportunities for participating companies and banks.

Explore blockchain trade finance solutions

Explore blockchain for supply chain solutions

Explore blockchain trade finance solutions

Related Solutions
Supply chain transparency

Create a blockchain ecosystem to share data with your supply chain partners, with transactions that are more efficient and built on trust.

Learn about IBM Blockchain Transparent Supply
Blockchain for trade finance

Pull down invisible barriers to growth and reinvent trade and trade finance with our network-convening expertise and the industry’s leading platform.

Learn about blockchain for trade finance
Blockchain for food supply

Growers, distributors and retailers can build trust and make our food safer, by enhancing visibility and accountability in every step of the food supply.

Learn about IBM Food Trust™
Resources What is blockchain?

Learn from the ground up what blockchain is all about and how it can benefit your organization. At no cost to you, download a copy of IBM’s Blockchain for Dummies guide.

Blockchain industry applications

Remove friction, build trust and unlock new value with IBM Blockchain. See how blockchain is solving problems for businesses and industries and get inspired.

Blockchain solutions

You can join existing blockchain networks that are transforming industries by bringing revolutionary trust and transparency to supply chains, global trade, international payments, our food supply, and much more.

IBM Blockchain Services

Co-create with the industry’s leading blockchain services provider. We can help you build a scalable business network underpinned by the best technology.

Writing smart contracts

The IBM Blockchain Platform supports smart contracts written in Go and Node.js. Read this tutorial to learn how to get started writing encoded business logic, terms and conditions for execution on blockchain.

Deploy a smart contract on your network

If you are running an IBM Blockchain Platform network, this tutorial will guide you through writing, packaging and deploying a smart contract using Hyperledger Fabric.

Next Steps

Explore our informational guides to gain a deeper understanding of various aspects of blockchain such as how it works, ways to use it and considerations for implementation.

Blockchain Topics What is blockchain Benefits of blockchain Blockchain for business Blockchain security Hyperledger Blockchain for good Blockchain and IoT