No one likes to hear that you can’t keep to a budget but at the same time it is important to share how quickly you identified this and got back on track. Did you think creatively, negotiate more fiercely, did you slash expenditure in other areas or identify a new revenue stream? It is best to avoid blaming others (even if it was someone else’s fault) but ideally you can discuss how you nearly come close to over spending but used specific measures and budgeting tactics to come in on budget in the end.