Is an actual recommendation letter (vs. the name of a reference) standard at the UK Lecturer or US Assistant Professor level? I'm currently 2/3 of the way through my first postdoc, and starting to look around at, and apply for, my next job.  I've noticed that some places require three letters of recommendation, whereas other places simply require two or three references -- i.e. they will call or email the referee if they view that as appropriate or necessary.

Writing an actual recommendation letter -- which typically has to be uploaded by the recommender -- is much more of an "ask".

Is an actual recommendation letter standard at the UK Lecturer or US Assistant Professor level?  The pattern I seem to be seeing is that more prestigious places are more likely to require an actual letter; would others confirm that?
Having made more that 50 applications for Lecturer posts in the UK, I can share some of my statistics.


Only 3 Universities of 50 asked for LoRs to be communicated through the applicant.
The majority, 47 of 50, asked for a list of references, and contact them asking for LoRs only if a candidate is shortlisted.


In the U.S. the customs may differ.