If you want a good reputation in your workplace, you have to show the other people around you that you are honest and that you can be trusted. Being honest will get you far and earn you more respect from your employers and coworkers. They will always be able to know that they can believe whatever you might have to say. Unfortunately, many people are not honest. They will tell a lie to get out of anything. In many cases, if you tell one lie, you have to keep telling more lies and remember exactly what you said before so that you will not get caught. I think it is better to just tell the truth the first time and face the consequences rather than maybe being caught later when you have told other lies and face the consequences then because it might be worse.
If you are person that has excellent integrity, then you are a rare breed. Most people today do not have very good integrity. Even if you do something that is wrong, if you own up to it and apologize, then people will respect you more.