Hello, I have a sole prop LLC small business and I'm in the process of changing the name of it, do I change name with the IRS now or can this be done as part of my taxes

name changes probably have to be filed with the state since LLCs are state law entities. 

I've changed the name with WA State DOR and I don't need a new EIN. So can I wait and add this change of business name into my next taxes? TIA