Have you wondered if the lying was a symptom of something else? I may be that you could put a bandaid on the symptom, and not get to the heart of his issue. It may just be that he has selected a bad strategy to overcome something he either does not understand or feels shame about, because it is a big step to start choosing to lie when they clearly know better.
I would be suspicous, since most of what you are talking about involves the executive functioning skills of some new independent expectations for a 9 year old child. This is a crossroads time, when in school, they stop learning to read and write and start reading and writing to learn. It is a whole new skill that involves conceptual application and a huge jump in independent working skills. Kids need strong organizational skills, and good executive function to manage these things on their own. For many children, if these skills are weak, even if they are just weak in relation to his basic skills, they find the transition very distressing. We say to them thing like "you are such a smart boy, why can't you remember to bring all this home" or "how do you expect to keep getting good grades when you don't do your homework on time?" For them, particularly if they were very good students in learning to read and write and do basic math, when they cannot organize themselves, they are not just bewildered by this inablity, they actually doubt the adults who ever told them that they were smart to begin with, since they have no clue how to rise to this new expectation using the very good skills that they already have. The hard thing to see, especially for them, is that these are completly different skills.
Getting his own breakfast could also be seen as an independent skill too, and if he was able to do this before, or you know that he is capable of getting something to eat when it suits him, know that getting something done independently in a sequence when you are overwhelmed otherwise with independent skills and organization would not seem unusual to me in that context at all. Getting ready to go to school without help maybe part of the new independence that he could be struggling with.
I would not suggest anything specific here, but if you recognize anything in my post that you think may apply, or if there are other educational concerns that might go along with this kind of issue, you could get an evaluation to see if he could benefit from some instruction in organization, or some coping mechanisims for a relative weakness in executive functioning, there are certainly ways to address the heart of the matter that will be more effective than concequences, because he would not feel the need to lie to you any more.
It is really common for kids to choose what we might see as a bad behavior when they are overwhelmed with something that makes them feel stupid or like a failure that they cannot manage to fix on their own. It seems crazy to us to not just say "I don't know how to do such and such" but for many children , they choose to be in trouble for lying, or misbehavior.
Just a thought, I would talk to your son's teacher and see what he is doing in class, you may find more patterns that will help you.
M.
