Large businesses handle significant purchases (about 80% of overall spend) through carefully negotiated, secure, and long-term contracts. In the other 20% of purchases, big volume low value transactions are too fragmented to warrant dedicating resources to handle. These are called tail-end, long-tail, or low-value spend. Off-contract expenditure, tactical/spot buys, fragmented spend, commercial cards, expense reimbursement, non-po invoicing, one-time vendor spend, unclassified/misclassified spend, and maverick spend are all covered. It have : Hidden Tail: Spend with big suppliers not covered by contracts or non-compliant spend. Head of the Tail: Purchases from few suppliers and spend is not strategically managed (e.g., annually around $200,000 to $500,000 per supplier) Middle of the Tail: Purchases from many suppliers and not strategically managed (e.g., annually around $2,000 to $200,000 per supplier) Tail of the Tail: Purchases from many suppliers, spend is highly fragmented and transactional & includes many one-off purchases (e.g., annually less than $2,000 per supplier)