A promo code (promotional code) is a string of letters or numbers that, when entered at online checkout, reduces the price of an order. The discount can be a percentage, a flat amount, free shipping, a free gift, or a bundled deal.
In practical retail usage these terms are interchangeable. Different brands use different conventions — travel + entertainment platforms (Uber, Booking.com, Lyft) usually say "promo code"; fashion + general retail (ASOS, SHEIN) often say "discount code"; UK retailers tend to say "voucher code". They all mean the same thing.
When you enter a code at checkout, the merchant validates it server-side against four conditions: does it exist, is it within its validity window, is the global usage cap still open, and does your cart meet any minimum/category requirements? If all four pass, the discount applies.
Text entered at online checkout to unlock a discount.
Yes — these terms are interchangeable in retail use.
Verified coupon sites like CouponHuntz, brand newsletters, affiliate networks, browser extensions, and brand loyalty programs.
Expired, below minimum order, excluded category or payment method, region-locked, or usage cap reached.