When do I receive letter from embassy? (K-1)
 

My case changed to “ready” on the ceac website on Tuesday. How long until I receive mail/email from the embassy(London) so that I can book an interview?

I have completed DS-160 and the readiness form and gathered all required paperwork

Re: When do I receive letter from embassy?
 

I got mine within a few weeks. You should be able to schedule medical and interview without it.

Re: When do I receive letter from embassy? (K-1)
 

As Tom said, you should be able to book your medical and interview without it.

To add in case you weren't already aware - the visa is valid from the date of the medical and not the interview date.

Re: When do I receive letter from embassy? (K-1)
 

I think it took my letter around 1-2 weeks to get here. But my fiancée emailed the NVC and we got an email with our case number on.

You’ll need your case number to book both your medical and interview. The medical requires the letter when you attend but I just showed them the email with my case number on and that was fine.

Good Luck!