If you are a small or medium business owner and you do not have a permanent phone line at your disposal, then a great way to have one is by getting a toll free number. What is a toll free number? It is a number that is used exclusively for customers and clients. There are two types of numbers that are available, the private toll free and the public toll free. How does a private phone number differ from a public phone number? When you get a toll-free number, you will have an unlimited number of calls to make. In other words, you can call anyone that you would like to talk on the phone. Now, with a public phone line you can only call those people whose number you have gotten from the phone company. So if you want to call your daughter up and tell her how important her doing her homework is, you may be able to get through, but she will not be able to call your boss to let him know how important he is to her.
The downside to having a public telephone number is that it can attract unwanted visitors. If you get a lot of prank calls or annoying phone calls, then you will want to have a way to put a stop to these. Unfortunately, you cannot stop everyone who calls you because you are bound to have a few that will never be interested in leaving. However, you can take control of some of these phone calls by having a private number.

While there are several good reasons for using a toll free number, there are also some bad reasons. One reason is that there are many times when you will want to have a single conversation with a customer and all you have to do is pick up the phone and give out his or her information. This can actually work against you, as the other person could call back and ask you personal questions about why you are calling them.
On the other hand, there are plenty of times when using a private number is a good thing. For example, if you run an apartment building or a condo, then you might want to get rid of the receptionist, because a call center might be better at handling incoming calls. It might also be more efficient to have one person answer the phones instead of having a receptionist. If you work for a call center that works around the clock, then this can mean saving you a great deal of time and possibly money. If you run a business where customers call in constantly, then a private number is a good idea, as you will not have to keep the same phone lines and face the same problems day after day. The only problem is that some people who have multiple numbers might have problems connecting to certain services and this can lead to long hangs on the phones. Read more about dialer app on this post.

In order to find the best toll free number for your needs, you will want to find out what type of plan or package you have. If you are calling internationally, then make sure that you choose a toll-free number that works internationally. This will mean that your callers will not be charged extra fees, but rather a flat fee for international calls. If you are calling domestic, then choosing a local area code is often the best choice, since it is more localized.

Here is a post with a general information about this topic,check it out: https://en.wikipedia.org/wiki/Dialer.