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It’s likely that in everyday use, many offers and counter-offers are oral rather than written (except with real estate). However, it is crucial to have a written contract. Some states require that contracts be written in order for them to be considered enforceable. An oral contract, even if legal in your area, is far more difficult to enforce if one side does not hold up her side of the contract.  All states determine that some contracts fall within the "statute of frauds." Contracts involving land or real estate, contracts by an executor of a will to pay the debts of an estate, contracts for goods over a certain amount (usually $500), and contracts that will last longer than one year must be put in writing.  There is no concrete, presentable evidence of a verbal or oral contract. If you and the other party later disagree on what the terms of the contract were, neither of you will have proof that your opinion is correct. Courts find it incredibly difficult to rule on verbal contracts. For this reason, any contract involving important, expensive, or time-consuming consideration should be written. The contract itself should have a name (something simple such as “sales agreement” or “service contract.”) You should also specifically name the parties involved in the contract. If you are going to use a contract repeatedly, you can provide a shorthand representation (such as “buyer” and “seller”) throughout the contract, provided that there is a place to provide the legal names of the parties involved early in the contract.  For example, you might have a “Sales Contract” for the sale of your boat to your neighbor. You will need to specify the buyer, Jane Smith, and the seller, John Henry, in the beginning of the contract. If you have a recurring contract, such as for your photography business, you may wish to identify a shorthand representation such as “photographer” and “client.” You would say, in this case, Jane Smith (hereafter “photographer”) and Robin Jones (hereafter “client”) the first time the names are introduced. In the remainder of the document, you can provide “photographer” and “client” rather than specific names. The contract needs to specify the exact terms of the agreement. If you are exchanging goods or services, the specific goods or services should be specified along with the expected return (money or an exchange of other goods or services).  You may also want to provide specific details about what will happen if the expected exchange is not upheld completely. In particular, consider whether there will be "damages," or remedies for what happens if the contract is breached. There are several types of damages, and they are appropriate for different situations.  Liquidated damages are penalties instituted if the contract is breached. For example, if your neighbor buys your boat but is late with one of the payments, a liquidated damages clause could state that she will have to pay an additional amount of money for each week the payment is late. You have to be careful with these types of clauses; courts may not want to enforce clauses that seem too much like a punishment. A late fee is likely to be considered a reasonable liquidated damage; requiring your neighbor to return the boat regardless of how much they have already paid you is likely to be considered overly punitive.  Consequential damages are indirectly the result of the breached contract. They are often difficult to recover.  If the contract deals with something very expensive or time-consuming, you may wish to include a statement that disputes will be resolved through arbitration or a court proceeding. For example, if you are selling your boat to your neighbor, you should specify the make, model, and year of the boat as well as the name of the boat (if it has one) and a serial number if possible. You should also include the exact dollar amount and the terms of the payment. For example, you may specify that your neighbor will pay you $500 per month for 10 months until the $5000 payment is made. Many contracts, especially those that are for longer periods of time, have a termination clause. This clause lets all parties know how to legally "get out" of the contract without being held responsible for breaching it. For example, a rental agreement may specify that the renter may terminate her lease early by giving 30 days notice and paying a fee. To ensure that your contract is as specific as possible, be sure to include exact dates. If you want to provide a deadline but events or actions need not occur on a specific date, you can use the phrase “on or before” preceding the deadline.  For example, you may put in a contract that your neighbor is going to take possession of your boat upon the first payment, to be made on or before June 1, 2015.  She will then pay $500 on the first day of each subsequent month until the full $5000 payment has been reached, on or before April 1, 2016. If the contract is for the sale of goods or property, provide a clear, fully detailed description. For example: "Jane Smith agrees to purchase a white 2010 twenty-foot pontoon boat from John Henry." Allow space for all parties involved in the contract to sign and print their names.  You should also leave a space for providing the date that the signature is affixed to the contract. You may want to have a notary (or at least a 3rd party witness) witness the signatures and sign the document.  Even if this is not a requirement for your contract, it could come in handy if one party later claims that the document was forged or modified. Witnesses or notaries are normally required for wills, deeds, mortgages, and marriage contracts, depending upon state law.

Summary:
Have a written contract. Name the contract and the parties involved. Lay out the terms of the contract. Include a  termination clause. Provide dates and other details. Provide a signature area.