I used to download the ΔT and UTC data from the US Naval Observatory (USNO) server (maia.usno.navy.mil/ser7). But that was shutdown some time ago.
Took me a while to find an alternative, but they can be downloaded from this NASA server: https://cddis.nasa.gov/archive/products/iers/. It requires registration (for free!) but always has the latest data.
