Contracts undertaken in fraud of creditors when the latter cannot in any other manner collect the claims due them.

A contract that has a false cause.

Contract of sale where the consideration is in Korean Won.

Oral sale of immovable property for PHP 450.

Sale of house to be inherited by an heir.

Sale of a guardian of the property of the ward valued at P100,000 for P70,000. 

Oral lease of a car for 3 years.

Oral contract for the sale of a bag for P1,000, and it will be delivered after 18 months, and the payment shall be made upon delivery.

Absolute deed of sale for a land where the price is not indicated.

Contract where the signature of one of the contracting parties is forged

Sale of a public plaza.

One of the contracting parties lacks legal capacity.

One of the contracting parties is 75 years old.

A contract entered into by a person while insane during a lucid interval.

A contract where one party is a minor and the other party is insane.

Donation of human blood. 

Absolutely simulated contract.

Contracts where the consent is vitiated by mistake, violence, intimidation, undue influence, or fraud.

A contract entered into in representation of another without authority.

Sale of human kidney to purchase an iphone 17 pro max.

Contract of sale of a gun to assassinate the president.

Oral lease of a condominium for 10 months.

Notarized sale of a house with 1 garage and a garden.

Oral sale of a beauty pouch milk worth Php 499.