Q: When writing a resignation letter should I list where I'm going to work? If I don't list it and they ask, am I obligated to tell them? I am returning to my former employer. I left my former employer on great terms and only because they weren't sure our contract would be renewed and I was facing a possible layoff. Thank you.
A: Offering your resignation in writing is a professional courtesy. I strongly recommend writing a letter of resignation to your company and providing at least two weeks notice. In some roles, a longer notice period may be appropriate.
Your letter should be addressed to your manager and some employees will also copy Human Resources. It is a good idea to verbally communicate your intent to leave the company directly to your manager in a private, confidential way. Then, you can provide your written notice of resignation. Even further, it is always helpful to create a transition plan so when you leave, it is bit less chaotic.
You have no obligation to tell your company where you are going although certainly you will be asked by someone: your manager, co-workers, vendors or clients. I think it is fine to explain it as you state it in your question. “I am returning to ABC. I left on great terms and I really enjoyed my role there. The commute was a breeze too, only 10 minutes in the morning.” Most of your colleagues will understand and wish you well.
You want to ensure that you depart on positive terms. Yes, returning to your former employer might be a very good move for you but you also want to avoid creating havoc with your departure. You want to speak about your current employer, manager, workplace and colleagues in the most positive way possible. Some day, you might be working with some of these people again. It is a very small world.