ILR application with dependents

Hi,

Could someone please help answer the below -

I'm currently on Tier-1 (Gen) entry clearance status and planning to apply for my ILR in couple of month's time as "in-person application".
My dependents (my wife and son) both have been in the UK for all the time I've been. They are currently in country as my dependents- Tier-1 (G) dependents.

Do they have to apply with me for ILR or can I apply first and they apply a month later assuming that my in-person application is successful?
Or do we all have to apply at the same time?

Thanks.

If you satisfy cohabitation requirement and English language requirement then you and your dependents can apply in the same time. or if you want to apply first and then your dependents later then you can do that way also. But they can stay with their current visa until it will expire.

Thanks @haiksuresh.

Could you please point me to Home Office documentation/policy link regarding this. I tried to find a lot however no luck.

Thanks again.