I hope you mean a Tax ID Number ( SSN or ITIN ) and EIN ( Employer ID Number ). To get an ITIN -- if you are preparing for 2017 return -- you will need to visit IRS website and get the details ( down load the form required and details of all the required documents ).
If you are trying to file jontly with a non-resident -alien, for 2016, you can do the following :-- (a) print out your return, (b) in the space for the SSN of the spouse write in by hand the word "NRA" ; (c) fill out the application ( W8 ) for ITIN, include all the documents required; (d) include a statement that both you and the non-resident alien want to be treated as resident of the USA and thus exposing the non-resident's wotld income to USA taxation; (e ) mail in the return. This will result in ITIN being issued retrospectively for the year 2016.
If you are trying to file Married Filing Separate for 2016 with a non-resident alien spouse, follow the steps (a), (b) and (e) above.
Hope this covers your question
