First have a discussion with your spouse and decide together what the two of you are doing. You have two choices----
Wait for his return to be processed and amend it to file a joint return by adding all of your information and income to the separate return that he filed
Change your own rejected return to married filing separately and re-file it
If you decide to change yours to MFS then you have rules to follow----and married filing separately is usually the worst way to file.
If you were legally married at the end of 2020 your filing choices are married filing jointly or married filing separately.
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 $24,800 (+$1300 for each spouse 65 or older) 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 special rules for filing separately include: you cannot get earned income credit, education credits, adoption credits, or deductions for student loan interest. A higher percent of your Social Security benefits may be taxable. Your limit for SALT (state and local taxes and sales tax) will be only $5000 per spouse. In many cases you will not be able to take the child and dependent care credit. The amount you can contribute to a retirement account will be affected. 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)
If you are using online TurboTax to prepare your returns, you will need to prepare two separate returns and pay twice.
If you decide you will amend the MFS return to a joint return:
If you decide to change your own rejected return to a separate return---go to My Info and change your answer ---when it asks if you were married you say yes---when it asks if you want to file together with your spouse say NO
You will have to go through the screens and remove any of his income etc that you entered when you thought you were filing jointly