Reject R0000-902-01: Taxpayer TIN in the Return Header must not be the same as a TIN of a previously accepted electronic return for the return type and tax period indicated in the tax return. It means that a return with the taxpayer's or spouse's Social Security or Taxpayer Identification number has already been filed with the federal government.

assuming correct tin's on extension you can no longer efile. anyway the extension is now invalid because it is late.  not really an issue if due a refund.  however, could your husband have already submitted the return or you might be the victim of identity theft where someone has already submitted a return in your names. .

you can check  by either calling IRS or going to irs website and getting online transcript of 2018 return,