What is a DID (Direct Inward Dialing) Number?

Nowadays, businesses should have constant communication with their customers and clients. It is a must since a business presence is imperative to build trust. And as a matter of fact, your business should no longer be tied to a single telephone area code within their physical location.

And with the emergence of internet telephony. It makes it more possible to pick up calls regardless of your location.as if you are actually within the area associated with your telephone number.

What is DID number? This question might seem confusing especially if you are an amateur in the world of the telecommunication system. But don’t worry, we have you covered for all your concerns when it comes to the phone system.

DID number stands for Direct Inward Dialing. But in some parts of the world, they also refer to this phone system as Direct Dial-In (DDI). It means that DID allows you to route calls to an unlimited number of extensions. You can use this to assign a direct number to your employees without the requirements of physical equipment such as telephone lines.

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How Does a Direct Inward Dialing Work?

Usually, direct inward dialing is tied up with a PBX phone system of a company. When calls reach the PBX system, the system then routes the calls to the preferred destination.

To make it more precise on what is direct inward dialing does to your communication set up, it is important to specify what DID definition in telecom is.

DID number meaning in telecommunication doesn’t end with direct inward dialing. Rather, it goes a bit of a long way to fully understand how it works. With the help of this system, your business can provide a different set of numbers for various departments in your office. So if one of your customers uses this service and calls you about a particular concern, they have the freedom to contact the person responsible for resolving their problems directly. It is of essential matter for your business since it saves you time and provides excellent customer satisfaction, all in an amazingly low budget.

This means that your business can efficiently utilize a single DID number to route all incoming calls to your office’ proper extensions.

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What is required to have an Active DID?

To have an active DID service, your business is required to have working lines where inbound calls can be forwarded. Telnum provides innovative phone technology to make routing calls to your existing phone lines simply and efficiently possible. Your working transfer lines would either be a landline, digital line, or mobile phone.

How are DID numbers used with PBX systems?

The cloud concept allows IT providers to give both software and hardware. By acquiring cloud services, you eliminate the need to hire an IT expert since there is no need for maintenance for your software or manage your servers.

With call forwarding, once an incoming call arrives at one device, it is then transferred to another device. You might think that call forwarding is what PBXs job, but it is not the case. Private Branch Exchange (PBX) is not an endpoint, rather it is an exchange, as the name stands for. Thus, PBX doesn’t receive incoming calls, rather routes them to the proper destination.

About DID, the most essential advantage of having this service lies in caller IDs. And even though it is good to have the capability to forward calls to cellphones and other communication devices, your clients and prospects will always see the number if anyone on those devices calls them back.

What is the advantage of having a DID route your calls through a PBX system?

The main advantage of having a DID is that any individual has the capability of calling your extension or phone number, without the need for an operator and your organization doesn’t necessarily need to buy more telephone lines. It is a good thing to familiarize yourself with the benefits and advantages that come from a DID route call via the PBX system.

With more telephone lines and of course, means more telephone numbers, it is too complex and a rise in expenses will surely be noticed. The good thing is, there is a piece of hardware that can control this kind of situation – and that is PBX or private branch exchange. That may sound a technical term to you but it is as simply linking all the phones available in your company together.

Internal communications

If you think that your business needs to level up and acquire more phones in your office, what you necessarily need is to learn more and in-depth about PBX. Modern phone systems are indeed highly computerized, and others even operate via the Internet. As complicated as it may seem to you, the fact is this innovative technology just makes the PBX phone system so easy to manage. Don’t forget that aside from that, the modern PBX systems are more affordable as you might be thinking.


Having a PBX phone system for your business gives you an edge over other competitors. One of its advantages is the automation feature where you don’t have to hire a receptionist just to answer incoming calls. You might already have called an organization or business institution before and heard its “auto-attendant” instructing you to dial click a particular number for a specific department or service – and that’s what we call the PBX system.

Flexibility in Routing Inbound Calls

The PBX phone system has more efficient and helpful features compared to a standard or traditional phone. Let’s take this scenario as an example: You are waiting for a very important call. However, there was a sudden invitation for you to attend an urgent meeting in another office or location of the building. The best thing you can do is simply program your phone so the system will forward incoming calls to another phone if you can’t answer it within the given number of rings. This VoIP phone feature allows you to forward those calls to another device, or if you prefer, to voicemail.

This capability to forward incoming calls to another phone only means that you can even set up backup routing if needed such as when a sales manager goes out of the office. That particular incoming call will be forwarded automatically to another person in the team. This assures you that there would be no miscalls or unanswered calls.

Expense Monitoring

DID numbers routed to a PBX system keeps you records of your inbound and outbound calls. The ability to view the figures of incoming calls you received is a kind of feature that is not available in traditional phones, not until your phone bill arrives at your doorstep. This type of feature allows you to monitor which departments are receiving more calls than others, as well as seeing which ones are almost not receiving any calls.

This report of usage will certainly help you adjust your extension allocation so you can optimize the return of your investments in telephones. Aside from that, you will have the capacity to check whether your employees are making personal calls, the length of each call – identifying who is efficient in work and who is just hanging around.


Cloud-based PBX phone systems don’t need to be installed inside your business premises and therefore don’t need any additional equipment or hardware to be purchased on your part. It only means that you have nothing to worry about breakdowns, or malfunctions, or complexity in installing.

Once you remove the actual PBX box in your office, the expense of hiring technicians or maintenance experts is eliminated from your business phone system. This is one of the best advantages that PBX phone services have to offer you.

What is the Difference between Toll-Free and DID Numbers?

Before we figure out the difference between toll-free and DID numbers, it might be better if we explain a bit about the DID SIP trunk. SIP trunking via Telnum allows your incoming calls to be transferred through your business’ PBX to your preferred specific extension or individual through landline or phone. This is important so you would be able to identify and learn how this system works effectively for your business and customers, and how DID SIP trunk is related to your virtual numbers.

What is a Toll-Free Number?

It’s been considered a long time since the existence of toll-free numbers, and by using them in businesses, they have radically changed the way companies communicate with their clients. A classic distinction that can be easily identified about toll-free numbers is the three or four-digit codes that can be easily dialed from telephone lines but no extra call charges to the individual making the call.

Toll-free numbers work as an effective tool for your business’ brand recognition. Once you choose them correctly, then there is no doubt that your business or services/products being offered will remain on the minds of your customers.

What is D.I.D. (Direct Inward Dialing) Number?

What is DID, DDI, or local numbers? Well, just to eradicate your confusion, these three are the same and are being used interchangeably. DID numbers are directly connected to the PBX phone system. And since your IP PBX communicates with your SIP trunk, the incoming call is being routed to preferred or specific extensions.

This is the reason why you need to know the relationship between SIP trunk and your DID numbers to avoid confusion on your part.

With DID or local numbers, you are creating a local presence for your business. Try to imagine a client using a toll-free number to reach your company. This scenario may put your business to be impersonal or too large. More often than not, customers prefer to deal with businesses that have a local presence or approach to them. It is far more convenient for them to transact with a local phone number than an 800 number (toll-free) number or unrecognizable area code.

Having a local presence by using DID numbers proved to be a useful and effective strategy if you are trying to increase your clients or customers in a specific location. Also, this gives a sense of comfort to your customers since they are dealing with a particular business that is just “next” to home.

Toll-free numbers and DID numbers offer the same great features that are very useful for your communication enhancement such as auto attendant and call recording. Both of them also can forward calls to specific destinations.


Whether you choose toll-free numbers or local (DID) numbers, it always depends on the specificity of your business needs. Either way, Telnum provides both of them, offering multiple global interconnects. Getting started with Telnum’s DID numbers can be quickly and easily set up online.

Get in touch with your customers cost-effectively and efficiently with Telnum’s innovative business telecommunication services.

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