Admit it or not, the title made you think of all the times when lying was the only credible choice you could make, but your conscience weighed you down nonetheless. If you can stop questioning your morals for a second, you'd realise that lying is indeed justified under certain circumstances.
In a formal setting or a workplace, telling big lies like lying about one's qualifications, putting the blame on others, and so on are definitely a BIG no-no. But then there are situations when it is perfectly okay to fib:
When you’re late
Now if you have a habit of oversleeping or are otherwise too lazy to meet deadlines, lying wouldn't get you far. But if you've genuinely had an unfortunate incident that caused you to be late, but you can't reveal the details, it's fine. People don't honestly care about the reason for being late—they just want to see the sincerity that you feel bad for making them wait.
When you’re protecting a co-worker
This doesn't mean you should be covering up crime. If your co-workers have done or been in a compromising situation, you don't really have to be the office tattler. Safest is to ignore it altogether even if you found out about it.
When the boss made a lame joke/asked about their appearance
All you do in such cases is stay quiet, pass it off with fibbing or just make any polite gesture if you know your answer isn't going to be one they 'expect' to hear. You wouldn't want to provoke a bad attitude towards you in any case, would you?
When you want to quit a job you hate
You might hate your current job because of your obnoxious boss, poor job prospects, low pay, etc. but you don't have to go about spilling it out. Just fib and say you left for personal reasons rather than ranting—maybe Donald Trump gets away with criticising others but you can't.
When discussing third rail subjects
If someone asks you about your personal views on politics or even religious controversies, it's best to make light of the matter and move on. Sometimes if your views clearly clash with that of others, always agree to disagree and acknowledge their viewpoint.
Negotiating for anything
Any form of negotiation requires you to hold strong arguments. If, for instance, you overstate any statistical percentages to help win a project or a bid, it's okay to exaggerate your last salary a bit to ask for a bigger amount. Or if your office gets to know that you're looking for a different job, it’s okay to not give away major details early on. Don’t lie blatantly, but your privacy is your own.
When you don't want to socialise
It is always good to bond with your co-workers beyond the formal arena. But if you don't have the right mood for a social gathering on a particular day, it's totally harmless to make up excuses and avoid it. Just make sure it's a good one.
So these are just a few in the arena of white lies. Play it safe and be diplomatic, but always turn to your conscience to know when to draw the line!