Splitit is a technology provider that enables merchants or retailers to offer monthly instalment payments to their customers by using the customers' existing credit card with no credit checks, interest, application forms or fees.
When you make your purchase the merchant or retailer takes your first installment payment.
At the same time the full outstanding purchase amount is authorized (held) in order to guarantee future payments to the merchant or retailer. These authorizations are renewed periodically (usualy every 21 days or so) and reduce with each instalment paid.
For this reason, you must maintain sufficient available credit on your credit card for the full outstanding amount of your purchase during the period of the plan.
The held amount might show as ‘pending transaction’ on your credit card statement.
You can find a full list of where you can use Splitit here.