My experience varies from what others have mentioned. My state pension was due to start on May 6th 2020 and it did. I received a letter several months before this date asking me to apply online three months before my pension date.
I tried to make the application in early February 2020 to be told applications were not being accepted until two months before SP age. I returned in March and got a message saying, I think, six weeks. I was successful the third time and it's a very simple process.
I was surprised when
@ColinJ posted sometime ago he had successfully applied several months ahead of his SP age. I just assumed the DWP had experienced problems and sorted them out. Nothing more or less.
I read of difficulties in SP payment. I wouldn't worry, it couldn't be more rock solid and provided you apply correctly you will receive your entitlement but it seems it could be late. It's possible the DWP have delays in other areas involving means tested benefits as these will always take time. SP is simple, a record exists, you qualify for a certain payment, the application is processed and the money should arrive on time.
The one thing I find confusing is the question of buying more years. To qualify for a full SP my wife has to purchase additional contributions. The dates by which this needs to be done are shown online. What I'm unsure of is do all the years have to be purchased at once or individually as the due date for each year approaches?
Again if this applies to you it will show online. The online info is simple and clear to understand apart from my query above.
https://www.theguardian.com/money/2021/oct/16/uk-state-pension-payment-delays-age-uk-dwp