A sale agreement legally binds the seller to transfer ownership of an item and deliver it to the buyer. In return, the buyer agrees to accept the item and pay the agreed price to the seller.

Information required for a Sale Agreement:

1. Details of the parties involved: Full name, parents' names, PESEL number (if unavailable, date and place of birth), residential address (and correspondence address, if different), identification document number, place of birth (city and country), and citizenship.
2. Land and Mortgage Register (Księga Wieczysta) number for the property or the cooperative right to the premises.
3. Price and payment method:
   1.  Whether any part of the price has already been paid (including any portion paid in cash upon signing the agreement), and if so, the amount and whether payment was made by cash or bank transfer.
   2. The deadline and method for paying the remaining balance (and if part of the price is from a loan, details on the down payment amount and loan amount).
4. Any other additional agreements.

Additional Information Required for a Preliminary Sale Agreement: (In addition to the information mentioned above):

1. The deadline by which the final sale agreement will be concluded.
2. Information about any potential loan for the purchase of the subject of the agreement (e.g., whether the buyer will be seeking a loan).