It's one of the payment plans that you could be offered at checkout with Argos Pay. It lets you buy a product now and pay nothing for three, six or 12 months, depending on which option you're offered.
You don't have to pay anything at all during the Buy Now, Pay Later period. At the end of that time, you can pay off the balance in full to avoid interest.
If you don't pay back the full amount, you'll start paying interest on the balance that's left. For plans taken out on Argos Pay, it'll simply be ongoing interest at your standard purchase rate, which you can find in the 'your account in detail' section of your statement. Find out more about how interest works for BNPL plans. Note, plans taken out on Argos Card may have a deferred interest charge, too.
After the BNPL period ends, you'll have to make at least your minimum payment each month – or more if you can afford it – until any remaining balance is cleared.