When is it a good idea for a couple to seek relationship counselling/therapy?

Ideally a couple begins couple's therapy while you can still look at your partner, more often than not, and think “Yep, I like that person”. Ongoing conflict in a relationship erodes the joy you experience in the relationship, the respect you have for the person and how you feel about yourself.

So I'd say if you find that you are having more arguments than good times or times of contentment, that's a good time to begin counselling. Having worked with many couples for many years, I've experienced couples at different stages of their conflict. Some come to therapy and it's really just the place they were looking for to end the relationship, others come and they are very ambivalent about the relationship and are trying to work out whether it's worth fighting for. Others know they want to stay with the person but know that if things continue, they won't want to down the track.

Either way, if you're wondering whether you should go to couple's counselling - that's often a sign that you have something to work out within yourself or with your partner.

I agree with Kirstin, if you are thinking of it as an option, it is time to move on it. In my experience the sooner you seek help, the easier, quicker and cheaper it will be. Do it now. All the best.

I really agree with what Kirsten and Grant have said. Often only one partner is willing to go so I'd say if both are willing and ready then go for it. Good luck

It is a good idea to seek out a couples counsellor when you and your partner are arguing more than before, when arguments are getting ugly for you, or when there is distance between you, or after an affair. Anytime that you feel it has become a while since your relationship was satisfying to both of you.
You need a referral from a GP if one of yu has an issue that can be assessed as a mental health problem and you want to claim under the medicare plan and the partner wants to help or feels that this mental health issue is impacting on your relationship. Otherwise you do not need a referral but can choose your own therapist or get a referral from your GP or friend.
Thanks 
Relationships should be a source of comfort and can be rekindled even after many years.

Some great answers above. In addition to this advice, make sure you seek out someone who is specifically trained in working with relationships (i.e. has specialist training in couples or family therapy). Professionals with this specialty have done extensive post-qualification training, and will have a separate qualification in one of these. These professionals will use evidence-based approaches - those developed by Dr John Gottman and Dr Susan Johnston are the 'gold standard' research-based methods - that will provide you and your partner with proven strategies to develop skills and perspectives that will help you to understand each other's perspectives and respond to each other differently, in a way that will help you to feel more connected and cared for.

I want to ask when isn't it a good time to seek out couple's counselling?  Why wait til there is an issue? 

Relationship therapy can help build resilience in your relationship and create the buffers to protect it from the mild relationship storms you may experience.

Enhacing your relationship communication is also a possibility.  As a sex therapist I often work with couples who wish to improve their sexual relationship too.

If you are thnking about relationship counselling then maybe it is the right time to seek relationship counselling!

Remember not every counsellor is suitable to every couple. Always talk to your counsellor and ask them about how they work, or how they can help you, to help identify if the person is right for you.