Error in my registration for self-assessment

Hi I recently registered for self-assessment. Unfortunately, in answer to the question “When did you start working for yourself or when did your trading allowance exemption cease?”, I accidentally typed the wrong year. What is the best way to resolve this clerical error? I was planning to wait to receive my UTR, and then enter the correct year on my tax return, and explain the discrepancy in the ‘other information’ box. Do you think this is the best solution, or should I contact HMRC now and ask to edit my registration form or submit a new one?

Hi,
If you have not yet received your UTR then I would resubmit the registration with the correct details. 
Thankyou.