Foreign born Children of a British citizen visa to reunite with parent in UK

[Patere]

Hi Here,

I need your advice please on which visa to apply to reunite my children with me here in the UK.
I am a British citizen living in the UK and I have 3 children born and living abroad with my spouse until recently. My spouse has now joined me in the UK 6 months ago with a 2y9mths spouse visa and we want our children now to come too.
1) Can I register my children as British so they can apply for a British passport to come in the UK?
2) If not, are they eligible for ILR as Children of a British citizen(the elder is 15 years old and the other 2 are less than 10 years old)?
3) If the 2 above won't work, what would be the cost effective way to apply for them to come?
4) Would it be my spouse or myself or both of us to sponsor our children ( with proof of income and so on...)
Thank you in advance for taking time to read and your guidance.

[CR001]

I have 3 children born

Were they all born before or after you became British? This is important.

1) Can I register my children as British so they can apply for a British passport to come in the UK?

No.

2) If not, are they eligible for ILR as Children of a British citizen(the elder is 15 years old and the other 2 are less than 10 years old)?

No. They need a visa in line with your partner and ILR when she qualifies.

3) If the 2 above won't work, what would be the cost effective way to apply for them to come?

There isn't one.

4) Would it be my spouse or myself or both of us to sponsor our children ( with proof of income and so on...)

You are the sponsor, but you can use both of your income.