Hello @FortressMelb and thanks for your question. Because you mentioned "e-vouchers" I'm going to think you're asking about sending out a digital "card" through email? If that is the case, you could create any sort of graphic or email that indicates you're giving this offer to your customers. Then set-up a discount in your Square Dashboard for an amount of your offer, for example $5.00. When a customer comes in venue to pay at the Register, you would ring up their purchases and then apply the $5.00 discount, which essentially applies this virtual gift card.
If you want some more advanced tracking, you could email an offer through Square Loyalty. If you don't already participate with the Loyalty Program, it integrates beautifully with the Square Register and customers can check-in on the screen at checkout, and you can apply the code they receive through email for this discount. This makes tracking redemption super easy and allows for reporting to find out what promotions are best serving you and your customers.
Hope this helped you answer your question. Please let us know how we can help additionally. Happy selling with Square!
