You should tell them right away. Be honest and upfront. Sleep easy at night. Work without it hanging over your head. Here’s why: - The person who you inform ma

You should tell them right away. Be honest and upfront. Sleep easy at night. Work without it hanging over your head. Here’s why: - The person who you inform may have others within their organization to update. It reflects badly on them too when they find out last minute something won't be on time and can break all of their internal assumptions about their timeline. They have goals too. - Delays pile up. 2 days here, 4 there, a week on that other thing… before you know it you’re a month behind schedule. It’s much easier to discuss things incrementally than it is to spring the totality of all delays on them when they believe they’re much closer to a completion date than they really are. “But we’re only a week away, how is it going to take another MONTH?” - Finally, though we’d all like to think otherwise… clients often make some changes during projects. When those changes occur and you’re already on the same timeline, it’s much easier to discuss how the changes the client is requesting are going to affect the delivery date. This helps with their confidence in you, and their capacity for accurate internal debate about project changes/additions and what it will do to the delivery date. Estimating development time is incredibly difficult; most methods involve some kind of padding which is obviously not an exact science. There are always hidden rabbit holes, unexpected problems and tasks that were completely unaccounted for. If you’re transparent with the client and communicate when there is good news (hey, check out the xyz feature we just finished) as well as bad news like delays, most of them will understand.