Gone are the days of workers staying at the same job until they're ready to retire. These days, it's not uncommon for a given employee to work for five, eight, or even 10 different companies throughout his or her career. But moving on isn't just a matter of applying for a new role and nailing a series of interviews; it's also about breaking ties with your current employer.

Resigning from a position isn't always easy, especially if you have a manager you've come to like. If you're not sure how to handle your resignation letter, here are a few tips to keep in mind.

Resignation letter

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1. Be respectful

Even if your soon-to-be-former boss is an utter jerk, it's important to be polite and respectful when composing your resignation letter. Tempting as it may be to tell off that pompous piece of work, when it comes to your career, you never want to burn bridges -- because you never know when you might need a reference or, worse yet, find yourself in a situation where you're begging for your old job back. And if you're moving to a different job in the same field, the connections you've made through your old job prove to be useful in all sorts of unexpected ways.

You don't need to sing your boss's praises when you write your letter, but don't use it as an opportunity to criticize your company or air your grievances. Instead, keep your language professional and be clear about your intentions.

2. Give plenty of notice

The fact that you're ready to move on is something your boss will need to accept, but you can make things easier -- and do the right thing -- by offering a reasonable amount of notice before jumping ship. At a minimum, be prepared to offer your employer a full two weeks' notice. If you have the option to delay the start of your new job and give your current manager a bit more time, it pays to do so. This especially holds true if your role is such that no other person in your company is currently qualified to pick up the pieces in your absence.

For example, if you're the sole internal accountant at a small publishing firm, and no one else in your office has any clue how to manage the books, your company will no doubt have to scramble to find a replacement. Offering three weeks of notice instead of two might earn you some serious brownie points with your old boss, and as we just learned, you never know when that might come in handy.

3. Offer to help with the transition

It takes time to list a job opening, vet resumes, and schedule interviews with prospective employees. It therefore stands to reason that even if you're able to give more than two weeks' notice, your company may not manage to hire someone in time for you to oversee his or her training. If that's the case, and you're required to start your new role before your replacement is found, you'll be doing your company a major solid by offering to assist with the transition.

This might mean coming in on a random evening to sit down with that new hire and walk that person through your old processes. Or it might mean pledging to make yourself available for calls, emails, or questions. in any case, if you're looking to show your old company a degree of gratitude with a side of goodwill, state your willingness to step up even once you're no longer employed.

4. Thank your employer for the opportunity

While there's no need to wax poetic about your old employer's virtues, when writing a resignation letter, it never hurts to throw a little heartfelt "thank you" into the mix. If your manager served as a mentor of sorts and helped you grow your career, be sure to acknowledge it. You might even point out one or two examples where he or she went above and beyond. Remember, losing a good employee isn't easy, so if you're kind in your notice, it'll help soften the blow.

No matter your reasons for leaving your current job, there's no excuse not to end things on a professional note. Nailing your resignation letter will allow you to move on without damaging your name or reputation in the process. And you never know how that might come to serve you in the future.