It won't necessarily trigger a review by the IRS just because it's a Married Filing Separate return. You would determine who is claiming the children, mortgage info, etc. However if one spouse itemizes, both must itemize. If one spouse uses the standard deduction, both spouses must use the standard deduction.
Generally, filing jointly 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:
- Education benefits
- Earned Income Credit (EIC)
- Child and Dependent Care Credit (usually)
- Adoption Credit (usually)
- The same benefit married filing jointly couples get for itemized deductions, the Child Tax Credit, and capital losses (all of these deductions are reduced by half)
- The standard deduction if your spouse is claiming itemized deductions
- On top of that, if you live in the community property states of Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, or Wisconsin, you have to deal with community property allocations and adjustments, which adds extra work and complexity to your tax preparation chores.
Want to compare filing jointly vs. separately?
Why would I want to file separately?