Dependent children and FIS

Just filling out form for F.I.S, first time applicant. There's a section that asks about dependants, their ages and if they live with you. Hubby has a child from prev relationship, doesn't live with us but obv he pays maintainance. We have 3 kids together also.

He wants to put total number of dependants as 4, I think we should just put 3 as only they live with us. He says it should be 4 as he pays money to his child and his child comes to stay. I don't want to complicate the application as I can't afford to have it held up any longer then it has to.

What is the norm for people who have kids not living with them? Should I put no of dependants 4 and then just write in that childs box that no, he doesn't live with us - or is it easier to just leave him off the application altogether seeing how we don't get extra money for him anyway?

Sorry to sound like such a mercenary, I just don't want it sent back for being filled out incorrectly but also don't want to leave something like this off in case it IS important.

No doubt I'm overthinking it as per usual Thanks

Here's what the operational guidelines on FIS say about qualified children:

B Qualified Child/ren
A claimant must have at least one qualified child normally living with him/her or part of a family supported by him/her.

Or

In the case of parents who are separated, a parent who is wholly or mainly maintaining a former spouse can qualify for FIS. However, only one FIS payment can be made in respect of any family.

A qualified child is any child under age 18, or aged 18 to 22 if in full-time day education.

A person included in one particular family for any period for FIS purposes shall not be regarded as a member of any other family during that period.

http://www.welfare.ie/EN/OperationalGuidelines/Pages/fis.aspx

This guideline indicates that a separated parent whose child is not residing but is wholly maintained by that parent can apply for FIS. The same may apply to your situation.