In TypeScript, an interface can extend multiple interfaces, but if there are conflicts between the properties in the extended interfaces, the compiler will throw an error. This often happens when two interfaces define properties with the same name but different types, which TypeScript cannot resolve. To fix this, ensure that the interfaces being extended are compatible and don’t define conflicting properties. If conflicts are unavoidable, consider using a union type or composing the interfaces differently. Alternatively, you can refactor the design to avoid extending multiple interfaces altogether. Properly managing interface inheritance ensures that your TypeScript code remains clean and type-safe.