How to build credibility?

Credibility is built when a person honors his words so many times that people with whom he or she committed begin to trust his words. This does not mean honoring commitments a hundred percent of the time, which is humanly impossible as there are so many things happening around us that are beyond our control. What is important is the effort that we make under difficult circumstances to honor our commitments, and when it becomes impossible for us then how do we compensate. Disappearing after committing is not the way. On the contrary, if it seems like that any part of the commitment is not possible to be kept, then do we inform the party beforehand about the causes, and what we are trying to do about it., and in case if we have to back off then how we are compensating for our inability to fulfill a commitment., and if our falling behind has incurred some loss on the party then how we are attempting to compensate for that loss. 

At the end of the day what matters is how serious we have been about the interest of the party with whom we have made the commitment, and how we demonstrate that seriousness with honest intent. Self-awareness or the awareness of our ability to fulfill a commitment also matters as it is easy for people to overcommit without much consideration if they can fulfill the commitment or not. Often we are already occupied and accept a new job. This is not an issue of ill-intention, rather our inability to accept our limitations. So The question we need to ask ourselves is, are we honest without our selves, are we mindful of our limitations, are we considering a buffer for contingencies. A common example of a buffer is to ask for some extra time even if you know it will take like 5 days to complete a job, but still, you ask for 7 days just in case if there are contingencies. Also if surprises are common in your line of business, then are you honest about them with your stakeholder before committing? So in a nutshell, (a) honesty with oneself, and with stakeholder, (b) clear intentions, and (c) seriousness, and (d) consistent demonstration of these three qualities subsequently build credibility over time.