Almost all stores will allow a customer to get the (stores) discount with just a phone number.
But, NO store will give a employee discount, (unless) you scan your ID card, or even the normal discount card, which is tied to the HR system. But in both cases, they need a (card) to scan it. And, if you (loan) out your card, then usually with most stores, ONLY family members can use, which in most cases, a young person, then the parents can use that card, or sometimes, the store might give an (extra) card to use.
In one store, saw an employee buying something from the manager. Even though the manager knew the employee, could/would (not) give the employee discount till they had the card to scan. So, the employee had to get the card, then the manager (refunded) the 20% discount on the prior purchase.