18 Digit code for Class 3 NI Voluntary Contribution - expiry date?

Hi, I am looking to make a voluntary contribution of class 3 national insurance to close gaps in my state pension from previous years. I obtained from HMRC the 18 digit code to make payment which is now postponed until April 2025. My question is - will the 18 digit payment code remain live until say Jan 2025 or will it expire at an earlier date? Thanks

Hi John Gage,

If the amounts you have been advised you can pay, haven’t changed since you obtained your 18 digit reference – then they will be valid until April 2025. 

Thank you.