There are many reasons you might decide to leave a job. Maybe you have a better offer, perhaps you dislike the current work environment or maybe you need to be a full-time parent.
Often, it’s best to give a few weeks notice. This allows you to tidy up any loose ends and allows your employer to find a replacement. But sometimes you can’t or don’t want to wait that long. You prefer to finish the day or the week and move on from the company. The question then becomes, can you actually do this, or must you give a certain amount of notice to your employer?
Do you have a contract that stipulates notice?
If you have an employment contract, check it for mention of a minimum notice period you must give. Not all contracts have them, but many do. When they do, you are contracted to abide by that unless your employer permits you to leave with less notice. Clearly, they cannot force you to go to work and work out your notice period, but they may be within their rights to take legal action against you if you don’t or withhold bonuses.
What if there is no contract?
If you don’t have an employment contract, then you are effectively employed at-will. Both you and the employer are free to end your working relationship at any time without any obligation for notice from either side. That does not necessarily mean you should just walk out. If it complicates things for your employer or colleagues, it could harm your future job prospects, as employers often ask former employers or ex-colleagues they happen to know for their opinion of a person seeking a job with them.
Even if you are not legally obligated to give notice, your employer may try to tell you that you are or threaten retaliation, like taking you to court or withholding your last paycheck. If that occurs, it may be wise to seek legal guidance to clarify the situation and examine your options.

