Why do you want to compare Joint vs. Single? If you are legally married, filing Single is not an option.
If you were legally married at the end of 2025 your filing choices are married filing jointly or married filing separately when you prepare your 2025 return.
Married Filing Jointly is usually better, even if one spouse had little or no income. When you file a joint return, you and your spouse will get the married filing jointly standard deduction of $31,500 (+ $1600 for each spouse 65 or older) for 2025. You are eligible for more credits including education credits, earned income credit, child and dependent care credit, and a larger income limit to receive the child tax credit.
If you choose to file married filing separately, both spouses have to file the same way—either you both itemize or you both use standard deduction. Your tax rate will be higher than on a joint return.
Some of the disadvantages of filing separately include:
You cannot get earned income credit,
You cannot get education credits or deductions for student loan interest.
You cannot get the childcare credit
You have a lower amount of income on which to base the refundable additional child tax credit
85% of your Social Security benefits will be taxable even with no other income
The amount you can contribute to a retirement account will be limited.
Capital loss deduction is less than if you file jointly
You cannot get the $6000 senior deduction
You cannot get the deductions for overtime or tips
If you live in a community property state, you will be required to provide additional information regarding your spouse’s income. ( Community property states: AZ, CA, ID, LA, NV, NM, TX, WA, WI) and your returns become very complicated.
If you are using online TurboTax to prepare your returns, you will need to prepare two separate returns and pay twice since with online, you get one return per fee.
https://turbotax.intuit.com/tax-tips/marriage/should-you-and-your-spouse-file-taxes-jointly-or-separ...
https://ttlc.intuit.com/turbotax-support/en-us/help-article/income/getting-married-mean-taxes/L2Rgma...
https://ttlc.intuit.com/turbotax-support/en-us/help-article/taxation/married-filing-separately-commu...
It is not easy to compare MFJ to MFS using online TT but you can do it. Since you only get one return for each account and user ID, you have to use 3 accounts and user ID’s—one for MFJ and two for each of the MFS returns. Compare, choose, and file—and pay—accordingly.
It is much easier to do this comparison using the desktop version of TT installed from a CD or downloaded to your own computer. You pay once for the software and you can prepare multiple returns easily, and it has a “what if” feature that allows comparisons.
**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.**
