This question already has an answer here:
So I am in the final stage of the recruitment process and the presentation is scheduled in a couple of days. Over the weekend, I received an offer that I accepted.
Ideally, I would have waited for this final stage before accepting the other offer but the offer is from a company that ticks all my boxes and any delay would have left a terrible impression as well as caused delays in the agreed start date, which is not too far away.
How do I deal with the upcoming final stage presentation? Cancel it by informing the HR Manager? Inform the HR Manager of the accepting another offer? Just go ahead with the final stage and see what happens? Something else?