Adding Class 2 in the form, that is allready sent.

I sent form CF83 a while ago and appreciate that it is in a big pile but have now realised that I should have selected Class 2 and Class 3, not just Class 3, as I was working in the UK until I left and have been working in my home country since then. I think it would be helpful if I send a letter amending the form/adding further information but am unsure how to achieve this, i.e. how to ensure my letter gets linked to the form already submitted?

Hi Antanas1963,

If your letter is received before your CF83 application is processed (current timescale for applications from EU countries is 31 weeks and current timescale for applications from countries outside of the EU is 48 weeks), it will be shown as a related item on our records and will be looked at when your application is processed.
Please note if you are applying to pay at the Class 2 rate, you will need to provide details of your employment abroad i.e. full name and address of employer and exact dates of all employments or self-employment abroad. 

Thank you.