Although there are some benefits to complaining about discrimination, harassment, retaliation, safety violations, etc., anonymously, whether internally or by contacting an outside governmental agency, consider the significant disadvantage of complaining without using your name: even if the employer later finds out somehow that you were the one who complaint, they can take action against you, such as suspending, demoting or even terminating and then argue very persuasively that their action was not in retaliation for your complaints because they simply didn’t know that you were the one who complained. Even if they a good idea about who submitted a complaint, this will not be proof of that knowledge.
An employer cannot be liable for retaliation against an employee if that employer did not have knowledge or was not on notice of that employee’s protected activity. In other words, an employer can not be found to have retaliated for something the employer simply was not aware of that the aggrieved employee was doing.
It is especially worth using your name when making an internal complaint to HR or your superiors about your co-worker or manager’s conduct if you are sure that they will find out who complained even if you do so anonymously. In other words, in that case, you have nothing to lose. If you know you will be set up for retaliation, you might as well take a step to build a potential retaliation case and making it stronger by disclosing your name and putting as many of your superiors as possible on notice of your discrimination or harassment complaint.