Child first Passport need advice 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

Is he sending his renewal to the same address as his dds first passport application? I think you can do that if you put both reference numbers on the envelope. Has he given his exes passport number too?

If he doesn’t fill in the maternal grandparents details the application will be rejected and returned. He needs to talk to his ex - does she know he’s applying for a passport? If she knows and she’s fine with it then surely she’ll provide the info he needs?

You dont need the maternal grandparents details if OP and his ex provide their own passport details

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 !