My wife and I still need to file our 2020 federal taxes. It's now past the e-file deadline (d'oh). We don't owe anything, nor expect a big refund... just need to get the paperwork on file ASAP.
Since the only choice is snail-mail, how do we make sure we're mailing to the correct address? Is there a different address for late returns? Google & the IRS website haven't been useful on this.
It's not actually past any 'deadline'. Their 'Modernized eFile' system (MeF) accepts current tax/filing year and two immediately prior years -- but it does shutdown for a period in Dec-Jan to be updated for the new filing season; if that has already started for this year, you could efile TY20 once they reopen for PY22. But aside from waiting a while, you would have to go through a preparer or ERO who supports doing prior-year, which is not a very common need.
But to answer as asked, the address is not different. See https://www.irs.gov/filing/where-to-file-addresses-for-taxpayers-and-tax-professionals-filing-form-1040 and note in the box at the top: "... Form 1040 or 1040-SR for the current or prior filing years". Remember paper takes 3-6 weeks normally, and at present they're still short-staffed and working down the backlog from the closures last year, so be patient.
PS: I recommend (USPS) Certified Mail for paper sent to any government agency, including a paper 1040, but that's your choice.
