1. Actions for money had and received.
a) Money paid to another person to which the latter is not entitled. I.e., total failure of consideration.
b) Money paid by mistake.

2. Actions for money paid to the use of another.
a) Payment to a third party upon instruction to the debtor and notice to that third party - third party has a claim.
b) Payment by a third party (i.e. surety, assignee of a debt) against the principal debtor.

3. Actions for services rendered and benefits conferred.
a) Quantum merit claims in cases in which the other party has broken the contract.
b) Claims for a reasonable price for necessities supplied to a minor.