I am a “yes” person.

I was brought up to believe that saying “yes” was the polite thing to do (obviously strangers handing out candy was the exception to this rule).

When I entered the workforce, I was taught that saying yes would progress my career. It would lead to me being seen as a team player and having a positive attitude. It would help me get involved in a variety of projects. It would lead me to career success. Because successful people say yes, don’t they?

Well, it turns out they are also really good at saying no.

The problem with not saying “no”

The biggest problem with being a yes person is that other people’s priorities soon become your own. This is fine when you share the same goals, but it’s not ok when your goals are completely different. If Veronika from Sales is asking you to help her with an important PowerPoint deck because you are known for your own great presentations, this is a perfect opportunity to say no. While you may feel great by helping a co-worker, it probably means staying back late to get your own work done after you have finished Veronika’s slides.

When you perennially say yes to other people’s work, you end up working twice as hard. In a world where pretty much everyone is trying to find some resemblance of balance between work, family, friends, and having a life, working twice as hard because you are doing other people’s jobs is definitely not in your best interests.

So perhaps you can concede that saying no is important and will actually help you get ahead (rather than hinder it). But how do you get comfortable saying one of the most uncomfortable words in the English language?

It’s not personal

While saying no to someone feels deeply personal, and even quite rude, it’s not. When you say no to someone at work, remind yourself that you are saying no to the request, not the person.

When someone asks you to do something at work, it’s ultimately about doing a task that requires work. And time. If you have the time, then great! But if your plate is completely full, you are simply saying no to the task that is being requested of you.

Give a reason

Never say no without giving a reason. It allows you to say no and still come across as a polite and decent human being.

I often get emails from people wanting to catch up for a coffee. Some want to career advice, some want to work together on a project, some want to “pick my brain”, and some don’t even specify a reason.

Right now, as well as running my innovation consultancy Inventium I’m working on my third book and about to launch a couple of other big projects. I’m also busy being a mum. Needless to say, time is very precious.

So when I say no to people, as I do multiple times a week, I explain my predicament and say that because of this, I am on a “no-coffee diet”. In other words, I am not meeting with anyone where the conversation doesn’t relate to a specific project I am working on.

While this might seem harsh, I have found people on the receiving end are really grateful for my honesty and directness. Try it yourself.

If you can't say no outright, negotiate

Sometimes, saying no is outside of our control. Your boss might be asking for help on something, and it can be hard (and sometimes not in your best interests) to say no to the person who is responsible for progressing your career.

This is where negotiation needs to come in. Explain to your boss that saying yes to this project or request will mean saying no, or at least “not right now”, to other projects. Put the decision back on your boss.

If you know other people who have trouble saying no, share this article with them. Or alternatively, feel free to say “no”.

Dr Amantha Imber is an innovation psychologist and the founder of Inventium, Australia’s leading innovation consultancy. Amantha recently wrote a report about the 10 steps to creating your perfect workday, including how to eliminate distraction, turbo-charge progress on your most important projects, and the ideal way to end your workday. Access the report here.