Direct Inward Dialing (DID)

What is a Direct Inward Dialing (DID) number?

Direct Inward Dialing (DID) is often used interchangeably with telephone numbers. DID is phone service that lets numbers ring to a specific phone at a business, instead of routing to a phone tree, going to a menu, or dialing extensions.

How does Direct Inward Dialing work?

DID is a service provided by a local exchange carrier (LEC) that allows a phone call to ring to a direct line rather than having to pass through a phone tree or menu in order to be routed to its end location. The term originates from a time when it was more common for offices to avoid individual phone numbers for employees, and instead utilize extensions.

Now, businesses can offer individual phone numbers for its employees without requiring different lines into the private branch exchange (PBX). A DID may also be used for inbound faxes, telephony, and VoIP communications. 

Why do businesses use DID numbers?

Businesses are utilizing DID services as an easier way for their customers or clients to gain access to direct lines rather than being interrupted by an operator, placed on hold or navigating a phone menu upon calling. In turn, this yields a higher user/customer experience level. 

DID numbers can offer local numbers for your business regardless of whether you’re physically in the local community or not, as DID numbers are not restricted by geographical location. Implementing local DID numbers can increase a business’s probability of calls reaching potential customers as businesses typically prefer to work with other businesses in the area. Local DID numbers provide a personalized touch along with a higher level of comfort to the recipient of the call.

Some businesses are even using DID services for fax servers, allowing many of those users to have their own individual fax numbers. VoIP vendors will sometimes use a fax server to offer these communication services to their clients, since DID services have similarities to VoIP communications.

How much does a DID cost?

DIDs vary in price depending on the carrier you’re using, or the re-seller you what to purchase from, the type of DID you’d like (toll-free, international, etc.) and the country the DID will be based in.

Bandwidth’s DID price is $0.35 per line, per month.

Where can I get DIDs?

DID services may be purchased through any LECs or competitive local exchange carriers (CLECs). In countries that have a competitive market for local number providers, CLECs may sell DID services to businesses in bulk.

You can also purchase a DID through a VoIP provider. VoIP companies buy millions of phone numbers every month in major cities around the world. Being that VoIP numbers are not tied to a specific area code, if you purchase a DID through a VoIP provider, you will have a local number for any area code you’d like, and you can purchase as many as you’d like.

How is Bandwidth involved with DIDs?

Bandwidth supplies DIDs (phone numbers) as a part of our phone number management services. We hold one of the largest inventories of DIDs available, including local and toll-free, both of which can be SMS enabled. Bandwidth’s Toll-free voice comes with 5x carrier redundancy and you have the option to add on our hands-off toll-free disaster recovery services for your mission-critical toll-free traffic.

While providing DIDs is not unique in itself, Bandwidth’s APIs for ordering new phone numbers and transferring from other carriers are considered industry-leading.


What are the benefits of DIDs?

DID numbers let you provide individuals with their own numbers, without needing a physical line for every person or workstation.

This improves both employee and customer experience by removing automated menus and operators. It’s also a great advantage for companies with remote employees, quickly shifting office placements, and international teams.

What are common use cases for DID systems?

Call forwarding

You can forward calls from DID numbers to your team members’ voicemails, cell phones, and VoIP numbers, simplifying your company’s phone routing system and making it easy to reach on-call staff.

Conference calls and video conferences

DID numbers let your team members join meetings remotely. You can even enable numbers for individual team members, letting them host their own meetings at any time. This is a great use case for sales teams.

Contact center routing

Set up smart queuing for incoming calls with DID numbers that automatically send calls to the next available agent.

Expanding your team globally

You and your team can sometimes use DID numbers in multiple countries, which makes DID a great advantage for international companies.


There are few remaining use cases for faxing these days, but if you do need your customers or vendors to fax you, individually assigned DID numbers makes it much easier than giving out general numbers which are shared among machines.


DID numbers aren’t just for voice. You can use them for SMS text messages, which makes them a great addition to marketing and customer service toolkits.

Toll-Free calls

Make it easy for customers to get in touch by ordering DID numbers with a toll-free area code. Toll-free numbers mean customers are not charged the usual carrier fees for calling.

This post was updated on Feb. 21, 2024.