In nearly all countries any contract must be at "arms length". Otherwise you could do fancy things, for example regarding taxes. :-)
This is actually a reason why you can not, for example, enforce something that is given freely. E.g. I give you a contract where I promise you to give you my house for free. If I change later my mind, in many jurisdictions you could not force me to write over my house since there is not "arms length". It is something for nothing.
This is actually a reason why you can not, for example, enforce something that is given freely. E.g. I give you a contract where I promise you to give you my house for free. If I change later my mind, in many jurisdictions you could not force me to write over my house since there is not "arms length". It is something for nothing.
https://en.wikipedia.org/wiki/Arm%27s_length_principle