Question

I’m curious if Android NFC service allows the developer to start a Service (or IntentService for that matter) when NFC tag is scanned?

From Android Developers:

When a device scans a tag that has NDEF data on it, but could not be
mapped to a MIME or URI, the tag dispatch system tries to start an
activity with the ACTION_TECH_DISCOVERED intent.

It appears that only a new Activity can be launched, not Service, although it could receive the same Intent filter.

Answer 1

Although not the direct method, you could have a barebones Activity that will immediately start a service, then quit:

@Override
public void onCreate(Bundle savedInstanceState) {
  Context con = getApplicationContext();
  Intent srv = new Intent(con, TargetService.class);
  con.startService(srv);
  finish();
}