Saying “no” is one of the hardest lessons to learn in business. Of course you want to grow your business but you don’t want to overcommit or stress yourself out in the process.

When I started my etiquette training business 18 years ago, I joined just about every networking organization in town. Each one asked me to give a 20-minute talk, for free, in exchange for the proverbial chicken dinner. At the time, this was a great way to get some publicity and meet a lot of potential clients. However, I took on too many requests and felt taken advantage of and resentful.

Today, I realize the value of my time. I can’t give away my advice and seminars like I used to. I also realized that knowing how and when to say no is actually good for your health and sanity. If you sometime find it hard to say no, here are some suggestions.

1. Say no to toxic clients.

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When you have a stressful client – one that is more trouble than they are worth, or one that doesn’t pay on time – it can be beneficial to limit your commitments with them or discontinue the relationship altogether. Keep the lines of communication open by setting boundaries on what you will and will not accept and clearly state your company policy upfront. This will reinforce, not ruin, your relationship. At best, it will weed out those you shouldn't work with anyway.

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2. Say no to people asking for freebies.

When clients ask for a discount, a freebie or a special deal, think twice before you concede. You know what it takes to do your job properly and what you need to make in terms of income. Don’t let their request sideline your own goals or jeopardize your work ethic or reputation. Be clear as to why you are worth the price. If you feel compelled to give a discount, do so because you can or you really want the business. Or try asking for something in return, like a new client referral, a larger order or a long-term contract. Make it a win-win for both of you.

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3. Say no to overtime.

When you work in your own business, time can slip away and you end up working long, hours. As a result, you overlook your wellbeing, personal life and relationships. Learn to manage your time more effectively. Set work hours and enforce them. Let your clients and customers know your work schedule and when you plan to go out of town or take a vacation. If a client is willing to pay for overtime, you may be able to justify this sometimes-necessary burden by charging a bit more in order to complete the job.

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4. Say no to late payments.

Remember, you run a business, not a bank. Make sure your payment terms are clearly laid out in your contract and on your website, and enforce them. Don’t wait until you’re out of patience and resources to cut off someone who defaults on their payment. If absolutely necessary, you may have to take legal action. But beware; this is can be time consuming, stressful and expensive, so use it as a last resort.

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5. Say no to petty jobs.

Once you are working with a good client, it is easy to throw in a little extra work now and again. But beware of the client who asks you to “just do this one little thing” without offering to pay for it. If the request is easy and doesn’t take too much time, then go ahead and do it. Otherwise, saying yes to all these little requests can eat up your professional time, making it difficult to reach your income goals. Matter-of-factly offer a price for the extra work, even if it feels awkward to do so. Standing firm will indicate that your time is valuable.

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6. Say no to apologies.

Saying "no" is not a weakness, it is part of professionalism. You need to make payroll, pay your bills and make a profit, so there is no need to apologize for turning down work. You've invested a lot of blood, sweat and tears into your business. Protect it from time-wasters.

Saying “No” nicely, most likely does not come naturally and can take some practice. However, once you learn this skill, you will find that your clients will have a higher respect for your professionalism. You will also enjoy a higher income as a result.