You can claim online up to 4 months in advance of when it’s due. I got a text back within an hour, a letter within 3 days, and the payment went in on the right date.
They were super efficient.
But, a friend, whom did the same as me, same birthday, had to wait 3 months, after the date she should have been paid, for her payment, and a lot of people are having the same problem. Some problem with the system.
The online claim form was very simple and didn’t take long to do. Saves waiting for a form. ?
www.gov.uk/new-state-pension/how-to-claim
www.bbc.co.uk/news/business-59153546