How many previous year can I file for my daughters if my exwife never file taxes

Can I file for my two daughters for tha last three years if my exwife did not

can i file for my two daughters for the last three years if my exwife did notI live in ct and she lives in az my daughters are with me now

How long have they been with you?

Legally since 9/9/09

Would she allow you to file using them as a deduction? If she was the custodial ( primary ) parent then to redo your taxes you may need her permission for the deduction. They have new rules this year and if they were only with you for 3 months the previous year then you may not qualify for even that.