Accrual Accounting For Real Estate Commission

[realestateagent]

As a real estate agent I am paid a commission for completed transactions. My question is when using accrual accounting, when can I claim the commission on my books?

Can I do it when the sales contract is signed between the buyer and seller, with my commission then assumed to be forthcoming? When escrow closes? When the money actually hits my account after being released from escrow (sounds like cash accounting here). Another time?

Thanks for the help!