Deregistration confirmation

I filled the online form in to deregister as self employed 3 weeks ago, how long does it take for a letter to be sent confirming de-registration? I require confirmation for UC. Thank you.

Hi
The timescale for these forms to be processed is usually 3 weeks, if you contact our helpline we may be able to process this for you if it has not already been done.
Self Assessment: general enquiries
Thankyou.
Regards.