My ex husband gets to claim the children as dependents. When asked if I have children/ dependents, do I answer the question as No?

[DawnC]

Correct.   If you two are in agreement on him claiming the children and the related credits, don't even enter them on your return.    

Having custody of your child usually means you can claim that child as a dependent on your taxes.  But if you don't have to file a tax return, or you reach an agreement with your child's noncustodial parent, you can let them take the child as a dependent instead with Form 8332.

The child's noncustodial parent must be eligible to claim the child(ren)  as a dependent. The rules for claiming a dependent usually require the parent to live with the child for more than half the year. This rule can be waived when the parents are divorced, separated or live apart from each other.

[Mike9241]

assuming this is due to a separation or divorce agreement and that he has not lived with you and the children for more than 6 months in 2024. if you had them for more than 183 nights in 2024 - answer yes to having children

there's a question about having a custody agreement - so if this is the case answer yes

next question is the other parent claiming them this year - answer yes

you'll need to furnish your ex with a signed form 8332 which he must include with his return

https://www.irs.gov/pub/irs-pdf/f8332.pdf 

 this way even though you don't get them as dependents

you qualify for head of household and 

the earned income credit and child and dependent expense