Answer
Yes, income from the sale of real estate can be used to confirm the origin of funds. A real estate sale agreement is expressly listed among the documents that can be used to explain the source of the funds.
The logic is the same as with the sale of movable property, shares, or bonds: the contract shows the basis of the transaction, the asset, the parties, and the amount. However, it is better to supplement the contract with financial records so that it is clear how the money was received and where it was subsequently transferred.
For a bank or other receiving party, not only the statement “sold real estate” matters, but also the full set of supporting documents. The clearer the trail from the sale of the property to the current account, the fewer questions arise about the funds when they are transferred or when banking products are opened.