Section § 1473

Explanation

If someone fully completes what they agreed to do in a contract, either by themselves or through someone else they approve, and the person owed accepts it, then the obligation is considered fulfilled and is no longer in effect.

Full performance of an obligation, by the party whose duty it is to perform it, or by any other person on his behalf, and with his assent, if accepted by the creditor, extinguishes it.

Section § 1474

Explanation

If several people share responsibility for a debt or obligation, and one person pays it off, then all of them are freed from that debt or obligation.

Performance of an obligation, by one of several persons who are jointly liable under it, extinguishes the liability of all.

Section § 1475

Explanation

If you owe something to a group of people, you can fulfill your obligation by giving it to any one of them, unless the situation involves a shared deposit. In that case, different rules apply.

An obligation in favor of several persons is extinguished by performance rendered to any of them, except in the case of a deposit made by owners in common, or in joint ownership, which is regulated by the Title on Deposit.

Section § 1476

Explanation

If a person or group you owe money to (creditors) tells you to pay or fulfill your obligation in a specific way, and you do it that way, your obligation is considered finished, even if the creditor doesn’t actually benefit from it.

If a creditor, or any one of two or more joint creditors, at any time directs the debtor to perform his obligation in a particular manner, the obligation is extinguished by performance in that manner, even though the creditor does not receive the benefit of such performance.

Section § 1477

Explanation

This law says that if you owe a single debt and only pay part of it, the debt is reduced by the amount you paid, but only if the creditor keeps the payment willingly. However, if the creditor is forced to keep the payment to avoid harming their property, it doesn't count as willingly keeping it.

A partial performance of an indivisible obligation extinguishes a corresponding proportion thereof, if the benefit of such performance is voluntarily retained by the creditor, but not otherwise. If such partial performance is of such a nature that the creditor cannot avoid retaining it without injuring his own property, his retention thereof is not presumed to be voluntary.

Section § 1478

Explanation
When you fulfill a duty or promise that involves giving money, it's referred to as making a payment.
Performance of an obligation for the delivery of money only, is called payment.

Section § 1479

Explanation

This law explains how payments made by a debtor who owes multiple debts to the same person should be allocated. If the debtor tells the creditor how to apply the payment, it must be used to pay the specified debt. If the debtor doesn’t specify, the creditor can decide which debt to apply it to, provided it’s done within a reasonable time. The creditor should evenly distribute payments if there are similar debts owed both personally and as a trustee. If neither specifies, the payments are applied to pay off interest first, then the principal, then the oldest debt, and unsecured before secured debts.

One—If, at the time of performance, the intention or desire of the debtor that such performance should be applied to the extinction of any particular obligation, be manifested to the creditor, it must be so applied.
Two—If no such application be then made, the creditor, within a reasonable time after such performance, may apply it toward the extinction of any obligation, performance of which was due to him from the debtor at the time of such performance; except that if similar obligations were due to him both individually and as a trustee, he must, unless otherwise directed by the debtor, apply the performance to the extinction of all such obligations in equal proportion; and an application once made by the creditor cannot be rescinded without the consent of [the] debtor.
Three—If neither party makes such application within the time prescribed herein, the performance must be applied to the extinction of obligations in the following order; and, if there be more than one obligation of a particular class, to the extinction of all in that class, ratably:
1. Of interest due at the time of the performance.
2. Of principal due at that time.
3. Of the obligation earliest in date of maturity.
4. Of an obligation not secured by a lien or collateral undertaking.
5. Of an obligation secured by a lien or collateral undertaking.