Child first passport advice needed

[indieray]

Booked a holiday in the summer.
My partners applied for his own renewal passport
And his dd6 first passport. He has no communication with her mum (his ex) apart from handovers. They asked for her info name dob etc and his which he provided. He doesn't have the information of the maternal grandparents as no communication.
He gave his own parents dob etc but Doesn't have access to Their
Birth or marriage certificate, he has his dd full birth certificate which he will
Send but will this info be enough!
He's also wrote a note in their explaining the reasons and that he has his own passport application being processed too!
he's jus wondering if any of the info he's provided will be enough or cause
Delays. any advice would be appreciated thank you 

Does the mum know he’s applying for the passport?
is there a possibility she already has a passport?
This sounds like something that they should be discussing and arranging together, even if he pays for it as he’s the one wanting to take her on holiday.
No communication except for handovers is not an excuse for not providing all the required information and does not sound like a very mature coparenting relationship

He gave his own parents dob etc but Doesn't have access to Their
Birth or marriage certificate,

He can buy these.

He will also need her permission to take the child abroad

Ok Thankyou
His ex has an expired passport as far as he is aware. He had his own passport just renewed it a week ago so doesn't have the new or old passport no to give but did put in his application no for them to hopefully match it up !

And yes it is a very volatile relationship but he's advised the mum what he's doing she agreed to take their child abroad but that's it

I've just ordered my DD's first passport and it didn't ask me for anything relating to my parent's or her paternal grandparents. It just asked for mother's and father's DOB and passport numbers, and DD's birth certificate.

I'm wondering now if I missed a whole page of info I was supposed to supply.

No you haven't . It only asks for more info if the mother and father don't have a passport each to check. My partner is currently renewing his so cannot put an old or new passport down and gave advised them of this.
So I only think there are issues when neither can be verified initially!
They will defo send it back I think but he's also still got to send dsd full birth certificate so we shall see