Both 'moreover' and 'in addition' are correct and commonly used to add more information or emphasize a point in writing. They are interchangeable and can be used to connect ideas in a coherent manner.

Definition: besides Example: You should know I arrived in the office before anyone else. Moreover, it wouldn’t have been possible for me to be late, because it was my day off. Furthermore Definition: in addition Example: My dog is very well behaved. Furthermore, he never barks at strangers.

In addition often come in a LIST OF ACTIONS; rather formal or factual in tone. The company was reorganised. New members of staff were recruited. In addition, the managers were given new responsibilities. Besides is often used when we LIST DIFFERENT REASONS; more common in speech than in writing. I don’t want the job.

In addition tends to be more often used when describing a situation. For example, use in addition to add another action, fact, or the feature to a list that characteristises an object or concept. Unlike moreover and furthermore, in addition is not commonly used for arguing or supporting a viewpoint.