Smart contracts can be used in a variety of fields, from healthcare to supply chain to financial services.
1. Difficult to change
Changing smart contract processes is almost impossible, any error in the code can be time-consuming and expensive to correct.
2. Possibility of loopholes
According to the concept of good faith, parties will deal fairly and not get benefits unethically from a contract. However, using smart contracts makes it difficult to ensure that the terms are met according to what was agreed upon.
3. Third party
Although smart contracts seek to eliminate third-party involvement, it is not possible to eliminate them. Third parties assume different roles from the ones they take in traditional contracts. For example, lawyers will not be needed to prepare individual contracts; however, they will be needed by developers to understand the terms to create codes for smart contracts.
4. Vague terms
Since contracts include terms that are not always understood, smart contracts are not always able to handle terms and conditions that are vague.
Source : https://corporatefinanceinstitute.com/resources/knowledge/deals/smart-contracts/