The act of making receipts and deliveries of gas into an interstate gas pipeline or a local distribution company’s system equal with withdrawals from that pipeline or system. Balancing may be accomplished daily, monthly or seasonally, with fees or penalties generally assessed for excessive imbalances. The purpose of balancing requirements is to prevent a shipper from tying up storage and line pack with excess deliveries of transportation gas, or from depleting storage and line pack by taking more gas off the system than it delivers, both of which disrupt other sales and transportation services.