There are massive savings to be made by picking and mixing your telecoms providers yet, three years after deregulation, only 10 per cent of the residential market has taken advantage of the competition.

Irish consumers don't seem to realise that cheaper phones calls are only a call away. The largest savings are to be found on international calls.

A 10-minute daytime call to Britain costs £1.20 (€1.52) with Eircom. The same call costs 50p with small independent carrier Atlas Telecoms.

Many people are afraid to call Australia because of the prohibitive cost. But with 11,000 young Irish people on one-year visas Down Under, there are lots of parents, friends and family who want to keep in touch.

Smart Telecom offers a flat rate of 12p per minute all day, all week. That is very cheap compared to Eircom rates, which range from 34p to 67p per minute.

Anyone with a son or daughter in the US might be interested to know that the cheapest flat rate available is 8p per minute. Closer to home, a five-minute evening call to Germany is 50p with Century Home, 94p with Esat Fusion and £1.31 with Eircom.

So how can these relatively new and mostly small companies offer such good value? MinuteBuyer.com explains the concept very simply on its website.

"Telecoms companies are like airlines, except they're selling you call minutes instead of airplane seats. And like airlines, they often have excess capacity to sell - after all, you can't fly half a plane."

The new providers buy this spare capacity in bulk and pass on the savings to callers.

There are two broad categories of operators in the market - pre-paid and billing - although some offer both. You can use the pre-paid version of the service from your home phone, your mobile, a payphone or even a hotel phone.

With pre-paid calling, your account lasts for as long as it takes to use up your credit and you make calls through the carrier's switch.

To begin with, the customer must register with the company. This can be done by filling in a form, by calling, or through a sales agent. Several companies, such as Swiftcall and Switchcom, give special deals to customers who register online.

There are no set-up charges and no changes to make to your existing telephone service. Cheap rates can be accessed from any touch-tone phone.

The pre-paid residential services work on a pay-and-talk basis, where a new account is pre-paid and then used to make calls.

There is no need with this service to change your existing phone line with Eircom or even notify them that you are using another operator.

You can still continue to pay your bi-monthly line rental to Eircom but make whichever calls you choose using lower rates.

Generally a pre-paid service recognises your home number when you call the switch and you can dial the number you are calling as soon as you hear the dial tone again. You will need to enter an account number or a PIN when calling the switch from another phone.

The alternative is to move your land line to a different carrier, allowing you to dial direct from home.

Spirit Telecom entered the residential market two years ago with a very competitive offering but its customer base was recently bought out by Esat Fusion, which is owned by British Telecom.

Worries about the viability of unknown brands may be one factor holding some consumers back from the new players in the telecoms market.

There is no equipment to be installed or codes to dial when you switch to another carrier. It's just a question of filling out forms and giving the company authorisation to carry your calls.

When you start using the service, you will receive itemised monthly bills, which can generally be paid whatever way you choose. It is easy to combine this type of carrier with a pre-paid service, cherry-picking the best rates to suit your call patterns.

The companies providing this type of service in direct competition with Eircom are Esat Fusion and Smart Telecom. Chorus, NTL and Atlas Telecoms also operate in this market.

When you decide to move some or all of your business to different operators, the first thing to do is to go through your last itemised phone bill.

If your bill includes a high proportion of short daytime calls, pre-paid service Direct Dial Telecom is the best value. Local calls are 2.82p per minute at all times with Direct Dial, while national calls are 3.36p per minute at all times.

If you are comparing rates for different call types, don't forget to take discounts and special offers into account.

For short local calls in the evening, Chorus is the cheapest but after five minutes, Eircom is the cheapest. Unlike Chorus, Eircom also offers discounts to its customers.

Look out for set-up charges when comparing call costs. Esat Fusion levies a set-up charge of 3p on every call, which makes it less competitive on short calls.

Eircom has got the edge when it comes to national calls at the weekend, since the introduction of its 5p minimum charge. This means a 10-minute weekend call costs just 10p.

Esat Fusion offers pretty much the same rate for weekend national calls, plus the set-up charge.

With such a high level of mobile phone ownership, it is very difficult to avoid making calls to mobiles from a land line. Charges for mobile phone calls have remained high but there is choice and value to be found.

Swiftcall charges 15p per minute on weekdays, well below the Eircom rate of 22.8p.

There are smaller savings to be made on evening and weekend calls by shopping around.

It may seem like a lot of hard work but the savings are immediate and long-lasting.

Many companies will go through your bill for you as part of the sales process and point out savings they can offer. This is a good starting point but don't forget to keep looking for the best deal elsewhere.