A320 reported receiving engine oil LO warning on climbout; after coordination with company and oil quantity decreasing. Flight crew returned to departure airport and landed safely.

Narrative

We got an eng #1 oil LO press warning during our climb at around 20k feet. ECAM directed throttle to idle and shutdown engine if pressure below 10 psi. Oil pressure was indicating normal on the gauge and on the digital display so we didn't shutdown engine. I referenced the QRH which indicated that we could disregard the ECAM if the pressure indications were normal. Meanwhile we had leveled off and told ATC of our issue. PF (Pilot Flying) brought the power back up and we elected to continue climb. We told our company operations control of our issue and that we were currently continuing on. Then I noticed that our oil quantity was decreasing. I told our company ops control about the declining quantity and they passed it on to maintenance. We leveled off at FL310 and the PF brought the power back on eng 1 to see if the oil loss would subside. Meanwhile; our maintenance told us they'd prefer a return back to ZZZ and we concurred as it was closer anyway. We coordinated a return to ZZZ. I told ATC that we were losing eng oil quantity but that everything was running normally but to be aware we might declare an emergency if our oil pressure dropped. Fortunately; it was dropping slow enough that we had time to make it back to ZZZ without incident. We started the day with 20 quarts of oil and after engine shutdown in the blocks we had 8 quarts. Oil leak of some kind.If the oil leak would have been caught on the ground by maintenance.