For basic procedures regarding cancelling an order, also check Orders - changing an order - cancelling
Please see below for Magento statusÂ
Possible to cancel:
Pending: order creating internally - payment not received
Pending payment: payment not received
Maybe possible to cancel
On Hold: payment received - could be Dab order - check comments and status of shipment in Monta or with Stefano
Processing: payment received - check status of the order in Monta
Not possible to cancel
Complete: order has been shipped - cancelling is not possible
Closed: order has been refunded - cancelling is not possible