How to pay class 2 NICs already declared in self assessment?

I submitted my self assessment a couple of weeks ago. My self-employment income (my only income source) for the 2023-24 tax year fell below £6,725. During the self assessment process, I chose to voluntarily pay Class 2 National Insurance Contributions (NICs) totalling £179.40. This selection is reflected in the tax calculation summary (page 15 of 16) of the downloaded document I received at the end. However, I just received the official tax calculation letter today, and it shows no mention for Class 2 NICs. There's no mention of needing to pay them, and I can't find any information online within my account. Is it possible the Class 2 NIC payment will be calculated later? I'm a bit confused why there's no current mention of it, and I'm eager to settle this payment as soon as possible.

Any advice would be appreciated. I just want to pay my Class 2 NIC, but I don't understand why there is no option or mention of it, weeks after completing my self assessment?

Hi
You need to be registered as self employed for self assessment, in order for voluntary class 2 nic to be paid along with income tax.  In this case, you will need to contact the NIC helpline on 0300 200 3500, to voluntarily pay the NIC.  They will also be able to register you as self employed for tax and NIC for the next tax year.  Please note that you need a valid national insurance number to be registered as self employed.

But I am registered as self-employed. I wouldn't have been able to choose to make a voluntary contribution while completing my self assessment were this not the case?

I have just gone into the 'view your calculation' section and in the summary it says: Total amount due for 2023-24 £179.40 Total to be added to Self Assessment account due by 31 January 2025 £179.40 There's literally no other information on how to pay this online?

Hi Dan,
For details on how to pay, please refer to:
Pay your Self Assessment tax bill
Thank you.