Let's look at it from a somewhat different perspective!
To be eligible for the full State Contributory Pension, you will need to have a total of 2080
reckonable contributions on your PRSI record by the time you reach pension age (which can be any age between 66 and 70). [2080 is 40 years X 52 contributions]
From what you have written, your PRSI record will show at least 780 paid reckonable contributions from employment (15*52) plus the 65 you made in 2021-23, a total of 845. (You may also have reckonable credits, but you'll need to get your PRSI record to establish this)
So that leaves you needing to make another 1,235 reckonable contributions before you reach pension age. (That's about 24 years of PRSI).
The youngest age at which you can claim the State Contributory Pension is 66 (the oldest is 70). So, if you're currently aged 41 or younger and you pay PRSI every year until you reach 66, then you'll accumulate enough to ensure that you have a full pension.
But that's a minimalist approach, and if things go wrong, you may not be able to pay PRSI every year, leaving you short of contributions and making you continue to work after you have turned 66, which may not appeal to you.
So the advice is to accumulate as many PRSI contributions as you can at the current time, which will give you more options as you get older.
To make voluntary contributions, you need to complete the VC1 form (
LINK) (which is short and easy to understand) and send it to the address on the Form. Social Welfare will reply in a few weeks time and tell you what you will need to pay them in respect of each year. (The Form asks you what years you want to pay for and whether you want to continue making VCs annually). Before you set off, you might start by getting a copy of your PRSI record (
LINK) and seeing exactly where you stand. There's no hurry, you can apply to make VCs for up to 5 years previously.
Here's the Citizens Information page about making VCs:
Voluntary social insurance contributions can help you qualify for a social insurance payment in the future. Find out more about making voluntary contributions.
www.citizensinformation.ie