Unmarried partner visa question

My partner just wants to know what his role is during the appointment, and whether he needs to provide a letter as well as his documents.

His role is the sponsor.  If he's accompanying, then it would be obvious that he's present and settled in the UK so a letter would not be needed.  You are over-thinking this.

I don't doubt that! He was just asking me if we're going to be separated and interviewed, or if it's a more straightforward process than that, and I didn't know, so I thought I'd ask.

Worry about something else.   

An in-person application isn't an interview like you are thinking.  You will be called up to a window and the person will ask you for certain documents/evidence.  They may have additional small queries and again you usually have to provide documents/evidence to back it up.

It isn't a separated intensive quiz.  Remember in-person apps are supposed to be for straightforward cases and your evidence is still the star of the show.

i went through this 2 years ago with my partner.  she is uk citizen and was worried about what would happen at the interview.  Literally lasted about 5 minutes.  Nothing specific was asked really and just took the documents away and 10 minutes later came back and said i was approved and just had to wait for the printer to print my new visa.  in and out in 40 minutes.  

key thing is to have all documents in order and have as much joint accounts as possible to correspond with your address to prove you are together.  

Thanks everyone! I did an in-person appointment for my student visa renewal and that was pretty straightforward, but I just wanted to check this was the same sort of the thing. We have loads of evidence, and we're definitely a straightforward case. Thanks for the info!

GOT IT!!!!!! 
There had been a biometric failure yesterday (despite what they told me on the phone), so it was quite busy in Glasgow today, but overall it took about 2.5 hours for everything to be done, of which only about 5 minutes was spent talking to actual people. My partner didn't even have to say a word, just handed over his passport. I'm so chuffed! Thanks for everyone who answered my questions!

Yea!!!!!!!!!!!! Congratulations!

Just to close the circle, my Big Brother biometric ID card arrived today, 8 days after the visa was granted (though they tried to deliver a couple of days ago and I was at work). Happiness!