For security and fraud prevention reasons, we require six block confirmations on the bitcoin blockchain before funds are credited to the merchant account and the order is considered truly complete.
Note that block confirmation times are determined by the Bitcoin network, not by BitPay. One confirmation may take as few as several seconds to as much as a few days, but most transactions receive six confirmations within an hour if they have an appropriate miner fee attached.
If you would like to increase the likelihood of a timely confirmation, be sure to include a sufficient miner fee from your wallet. You can do this in the BitPay wallet by selecting the "Priority" fee option in your wallet's settings under "Bitcoin Network Fee Policy."