You give an employer a W-4 to tell them how much tax to withhold from your paychecks. Your W-4 only goes to the employer, not to the IRS. Your W-4 does not dictate how you have to file your tax return. The W-4 just affects the amount of tax that is being withheld.
You can go ahead and file a joint return if that is how you want to file. Joint is almost always better.
If you want to give your employer a new W-4:
https://turbotax.intuit.com/tax-tools/calculators/w4/
https://www.irs.gov/individuals/tax-withholding-estimator
https://www.irs.gov/pub/irs-pdf/fw4.pdf
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
