Self Employed - not sure if need to pay voluntary Class 2 NI

Macc

Apologies if the wrong forum, wasn't sure if should be this one or pensions.

I'm self employed, my first self assessment I've done in a while. Just about to pay my self assessment tax bill. Noticed I'm not down to pay any Class 2 NI contributions, just £756 Class 4. I've got a few years gaps where I'm missing NI contributions so need this year to count towards pension etc

My self assessment says:-

Profit £20,980
Tax £2093
NI £756

Would that be classed as a full year for pension?
 
I assumed that as my profit was more than £12750 I would have to pay Class 2 but it is showing as £0.00 owed in my self assessment. I'm fine with paying the voluntary contribution but obviously don't want to if I don't have to.

Can someone point out where I am going wrong 

• Less than £6725 I can pay voluntary but my profit is more than that
• £6725 - £12570 don't need to pay, will be classed as a full year, but I'm over 12570.
• £12570+ must pay but my self assessment says £0.00 Class 2 to pay

Jeremy535897

Are you sure that you are registered to pay class 2 NIC? This is a frequent problem where taxpayers register as self employed but fail to complete a CWF1. On your profit you are certainly liable. They won't let you pay voluntary class 2 either as you are actually liable for it. Contact HMRC.

Macc

Just seen your post but I did contact HMRC earlier and this was the problem. I registered for self assessment a few years ago for a small non-work thing I had. I assumed I just added my self employed work to that.