A custom that did not require purchasers of land to pay cash, although the terms of sale were for cash payments, will not sustain a contract of sale made by a real estate agent which violated an instruction to sell for one-third cash. Wandless v. McCandless, 38 Iowa, 20. Where a principal claimed that its broker had been notified of its custom to give only quitclaim deeds to purchasers of its real estate, evidence to show that after its refusal to give a deed with warranty, it offered to give such a deed if an increased price was paid was admissible to show that no such custom existed. Beach v. Travelers' Ins. Co., 73 Conn. 118, 46 A. 867. Where a custom exists among real estate agents and their customers which entitles the agents to commissions on a sale of land placed in their hands, whether the sale is made by them or by others, during the period it is under their control, such custom amounts to a contract when it is known to their customers. Harrell v. Zimpleman, 66 Tex. 292, 17 S. W. 478. See also Secs. 599, 626a.

A custom must be certain, uniform and generally understood, or it is not binding on the principal. Insloe v. Jones, Brightly (Pa.), 76; Pratt v. Bank, 12 Phila. (Pa.) 378; Colland v. Traped, 70 I11. App. 228; Potts v. Aechtermacht, 93 Pa. St. 138. An offer to prove a general custom among brokers acting for both parties to an exchange of lands to charge commissions to each, held properly refused, for the reason that it appeared that the broker was the agent of one of the parties, and could not therefore legally demand compensation from the other. Dartt v. Somnesym, 86 Minn. 55, 90 N. W. 115.

To a custom to the effect that each owner should pay one-half of the commission to the broker for effecting an exchange of property available as a binding custom, the broker must have acted as a middleman in the mutual interest of both parties, without being the authorized agent of either. Inman v'. Brown, 147 S. W. 652, - Tex. Civ. App. - .

That there was a custom that each party to an exchange pay 2 1/2% commission on his property would not authorize recovery of broker's commission from party to the trade who knew nothing of custom. Yockum v. Gassett, 200 S. W. 582, - Tex. Civ. App. - .

A real estate agent seeking to recover commissions for negotiating a sale, where no contract was made in regard thereto, may prove a custom as to the rate of commissions and the time of payment in the place where the business was done and the land sold. Hansbrough v. Neal, 94 Va. 722, 27 S. E. 593. See Sec. 616.

A custom existing among real estate brokers, according to which a commission is divided, where one broker has a buyer and the other a seller, is not sufficient to entitle the broker representing the seller, but not effecting the sale, to recover of a broker who was the procuring cause of the sale one-half of the commissions earned. Hedenberg v. Seeberger, 140 I11. App. 618.

The court takes judicial notice of a custom that authority to a broker to sell land carries with it the obligation to furnish an abstract of title. Watkins v. Thomas, 124 S. W. 1063, 141 Mo. App. 263.

In a broker's action for commission on the sale of a ranch and personal property, under an agreement that he was to receive "a good commission," it was not error to limit to 5% of the purchase price, which was the usual rate prevailing among local agents, and constituted a reasonable compensation. Burger v. Cole, 194 P. 611, - Colo. Sup. - .