How begin_checkout works
This event marks the moment a shopper stops arranging a basket and starts trying to buy it — the click on “Checkout”, or the first checkout screen loading. It carries the whole basket: every item with its identifier, name, price and quantity, the total value of the goods and the currency, and a coupon code if one has already been applied.
It should fire once per checkout attempt. If somebody backs out at the delivery step, returns to the basket and starts again, that is a second attempt and a second event. What it must not do is fire again on every screen of a multi-step checkout; the later steps have their own events for that.
Why begin_checkout matters
It is the anchor of the ecommerce funnel. Everything before it is interest; everything after it is a purchase in progress. The gap between checkout starts and completed orders is the single most valuable number a shop owner can look at, because it is the one place where lost revenue is both measurable and usually fixable without spending more on advertising.
It is also the sharpest audience you can build short of buyers themselves. Someone who reached the checkout and did not finish had a reason, and that reason is often practical rather than a change of heart — a payment method that failed, a delivery estimate that did not suit, a form that would not submit on a phone. In Nepal that last one matters more than most people allow for, because so much of the traffic arrives on modest handsets over patchy connections.
Common mistakes with begin_checkout
Firing it on every checkout step is the classic error, and it makes the funnel look as though checkout starts outnumber baskets. On a hosted platform, the opposite mistake is common: the checkout sits on a different domain, the tag is not present there, and the event never fires at all. Test the real checkout, not the theme preview.
Sending it without items is the third. The value alone tells you money was at stake but not which products were, so you cannot tell whether the abandonment is spread evenly or concentrated on a few lines. Keep the item identifiers identical to the ones used at the basket view and on the order confirmation, or the same product will appear as several in your reports.
How to act on it
Start by measuring the drop from checkout start to purchase, then watch it separately on mobile and on desktop. A gap that only appears on phones is a layout or a form problem, not a pricing one, and it is usually cheap to fix.
Then work through the checkout itself as a customer would, on a real phone: how many fields, whether an account is forced, whether the delivery charge and the payment options are visible before the last screen. Fix what you find, and use the checkout-starters audience for remarketing and for an abandonment email while you do. If the event is not firing reliably in the first place, that is the job to do first — an independent tracking audit will tell you quickly whether the numbers deserve any trust.