Child renewal:
Application submitted 12:11pm on 29 July 2021
Documents received 10:33am on 11 August 2021
Photo rejected 8:05am on 27 August 2021
New photo received 9:24am on 27 August 2021
Application approved 11:08am on 27 August 2021
Passport printed and sent 1:34pm on 27 August 2021
TNT due to deliver on 30th August 2021
I also applied for a First Child Passport, below, sent documents same day as above but they received it the following day.
Application received 7:34pm on 1 August 2021
Documents received 8:26am on 12 August 2021
Application approved 1:48pm on 28 August 2021
So assume delivery will be 31st.