Dsd passport advice needed please

[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 

He could order certified copies of missing certificates.

I didn't have all ex's info when I applied for DD's passport. My lawyer told me the most important docs are those outlining with whom the child resides (i.e. residence order / lived with order).

I didn't have any issues / delays. Just renewed DD's recently and didn't provide all ex's info ( no communication). It's been approved and just waiting on receiving the new one.

No expertise on what they may ask for but just a recommendation that he needs to act very promptly if they request more information - HMP Office are hopeless at recording proper notes if you call and departments don’t seem to speak to each other. If the application times out and is withdrawn, he’ll have to start all over again (and pay again). 😡

If he has his parents DOB, he can get copies for their birth certificates fairly easily from the GRO.
Are they still alive? If so, get their wedding date, and the certificate for that in the same way.

I'm pretty certain the ID you've given so far won't be enough, and you will need the certificates from at least one side of the family.

Yes this. Very simple to do this.

Has he actually applied for both yet? If time is on your side, it may be beneficial to wait until he has his passport (assuming a first time application?) until he applies for his daughter's.

I'm so surprised it's not more difficult to get a first passport without letting the other parent know.

He can't take her out of the country without mum's written consent.

Not unless he has a Child Arrangement Order.