You’ve been job searching for months. Your patience is exhausted, and so are you. That’s why it’s so important to be careful when you finally get that all-important call from your dream company offering you a job. Why? Because you might find yourself tempted to accept it right there on the spot. Not so fast.

Yes, it’s completely understandable why you would be thrilled and relieved but keep one thing in mind before accepting: it’s crucial that you ask for a written job offer before you verbally accept a position – even if it’s one that you’ve been waiting for all your life.

Why is it so important to have a written job offer?

Until you actually see the contract in writing, you really have no idea of what you’re getting. You might have a sense of what your base salary will be, but little else. Salary, of course, is very important but you also need to know the other parts of the job offer such as health insurance, vacation days and if applicable, maternity leave. All of these add up and you need to know what is really offered – or isn’t – before you say yes.

Let’s say you find out later that your job offer didn’t include basic short-term disability insurance, you’ve already put yourself in a poor position to renegotiate your contract. (For those that are wondering, companies really never negotiate on insurance, but if it isn’t offered in a written contract, you can use it as leverage to ask for a higher base salary.) If you say yes, and then try to go back and pretend you now have to reconsider the job offer, you’ve shown your poker hand already.

What to say when the call comes.

You need to prepare mentally to handle the silence after the offer call comes in and not fill it with a big YES of acceptance. What should you say instead? Something along these lines will work, “I’m thrilled to hear back from you and I can’t wait to look over the details in the written offer. When would you need my response?

This works 9 out of 10 times. However, you might come across a pushy HR representative who really presses you for a verbal acceptance before they draw up the paperwork for you. In fact, some companies won’t send an official offer without a verbal acceptance.

We don’t know of any company where this is actually an HR policy and we’re not sure what the motivation is behind this type of behavior, but when handling this situation, you should be mindful of your language. Reassure the HR representative that you’re enthusiastic about the position but that you’re just looking to get a feel for the details of the job offer before you formally accept. If this doesn’t work, you can say, “As of now, I see no reason not to accept this job, but I would feel more comfortable with a written offer in my hand.”

Rules vary by state on verbal contracts and they can be tricky business. The problem with at-will employment in the U.S. isn’t so much about being unable to back out of a job, but more about being unable to negotiate terms.

As long as you keep your wits about you and know to ask for a written offer before accepting a job, in most cases, the HR representative will send it along happily and allow you some time to think it over before you give a response. So, take a deep breath when you get that call and be prepared to negotiate.