2 responses:
1) if you are talking about where to mail your voucher and check it depends on what state you live in.
https://www.irs.gov/filing/where-to-file-addresses-for-taxpayers-and-tax-professionals-filing-form-1...
2) you might consider continuing to pay quarterly just in case your financial situation changes through the year. ( My personal opinion and does not necessarily reflect the view of the IRS )
