The Channel of Money (21-45) is one of the thirty-six channels of the Human Design bodygraph, a system originated in 1987 by Ra Uru Hu and described here as a modern esoteric framework rather than an ancient tradition. A channel is a defined pathway joining the Heart/Ego/Will centre and the Throat centre, and it is completed by two gates: Gate 21 ("Control Of Resources") and Gate 45 ("The Gatherer"), whose numbers come from the King Wen sequence of the I Ching. The channel idea and its Tree-of-Life-style pathways, the gates' I Ching numbering, and the centres' chakra roots were combined for the first time in the 1980s; the channel is part of that composite, presented as the system's own model, not as verified fact.
In the system's own account, the Heart/Ego/Will centre carries willpower and self worth, read as the capacity to make and keep material promises, and the Throat centre carries communication and manifestation, the single centre through which every other centre's energy is turned into speech or action; the channel is read as a direct circuit between those two functions whenever both gates are defined in the same chart.
The same two numbers appear elsewhere in this atlas as Gene Keys 21 and 45, Richard Rudd's later, contemplative reading of the identical hexagram pair. Gene Key 21 runs from the Shadow of Control through the Gift of Authority to the Siddhi of Valour; Gene Key 45 runs from Dominance through Synergy to Communion. Rudd's system drops the bodygraph and its channels entirely, so this particular pairing is a Human Design structure only, with no equivalent in his contemplative method.