All three new Galaxy Z8 foldables—the Z Flip 8, Z Fold 8 and Z Fold 8 Ultra—ship with just one nano-SIM slot, so buyers needing a second number must use eSIM.
Two lines can still run at once, but only as one nano-SIM plus one eSIM or as two eSIMs; the phones support up to two eSIM profiles, not three simultaneous lines.
The change is most notable on the Fold line: Samsung had offered dual nano-SIM trays on every model from the Z Fold 3 through the Z Fold 7.
For the Flip series, the limitation is less of a break from precedent, as global models have generally lacked dual physical SIM support aside from a few older regional variants.