Generally, filing jointly
together with your spouse will give you a bigger refund or less taxes due.
When you file separately, your tax rate is higher, and you won't be able to
claim certain deductions or credits. However, there are a few exceptions, in which it is more advantageous to file separately. Please see the following TurboTax FAQ,
"Is it better for a married couple to file jointly or separately?":
https://ttlc.intuit.com/replies/3288477
Please also see the
following TurboTax guide, "Should You and Your Spouse File Taxes Jointly
or Separately?":
https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Return/Should-You-and-Your-Spouse-File-Taxes-...