Comparing SIP Trunking Providers: 8x8 v. Nextiva

If you need a scalable, cost-effective cloud communications solution that will integrate with your existing PBX, you're probably in the market for a SIP trunking provider.

You’re also in good company. More and more businesses are looking to move their phone systems to the cloud without the expense of buying a new PBX.  As a result of this increasing demand, the SIP trunking market has grown, leaving you with the task of choosing from a wide selection of providers.

As a SIP trunking provider ourselves, we’ve decided to put our expertise to work and provide a side-by-side comparison of two SIP trunking providers: 8x8, Inc. and Nextiva.

Company Background

8x8, Inc.

With over 35,000 customers worldwide, 8x8 is one of the largest cloud communication providers on the market today.  In addition to being a leading SIP trunking provider, 8x8 offers a selection of VoIP solutions, including cloud-based call center software and virtual business phone systems.


Founded in 2006, Nextiva is a leading cloud communications company that serves the telephony needs of small to medium sized businesses.  Their main product offerings include hosted call center software, VoIP business phone systems, and PBX SIP trunking.

In 2014, Nextiva was recognized as one of the fastest growing companies in Deloitte’s 2014 Technology 500 Fast Ranking list.


Although there are some universal SIP trunking features, both 8x8 and Nextiva have additional perks.  Below, we’ve outlined the key functionality of both services.

If you choose 8x8 as your SIP trunking provider, you’ll enjoy:

• Free and unlimited calling between 8x8 enabled sites
• Unlimited concurrent calls
• Inbound and outbound service
• Pay-as-you-grow scalability

If you choose to use Nextiva as your SIP trunking provider, you’ll have access to the following features:

• Unlimited calling anywhere in the United States and Canada
• SIP compatible PBX support
• Flexible, cost-effective scalability
• Option to upgrade to HD voice quality

With both of these providers, you'll be able to preserve the investment you’ve already made in your phone system.  You can use your existing PBX and phones; Nextiva and 8x8 will simply provide the SIP trunk.


8x8 offers monthly and annual contracts for SIP trunking services.   These rates vary based on the length of the contract and add-ons, such as toll free and local numbers.

Nextiva offers two main service plans: a SIP metered plan and a SIP unmetered plan. Much like 8x8's pricing scale, these rates vary depending which additional features you choose to use.


Internet Fax Services

While some SIP trunking providers offer alternative options for traditional fax, others simply recommend that you keep a single landline for this purpose.  Both 8x8 and Nextiva offer Internet fax alternatives for businesses that choose to use SIP trunking, but still use fax on a regular basis.

8x8 offers several standalone plans for Internet fax: Unlimited Fax Extension and Metered Fax Extension.  Both of these plans are also available with a second port activation.

Nextiva offers three Internet fax plans that vary in price based on the number of pages that are faxed per month. These range from $4.95/month for 500 pages to $29.95/month for 3,000 pages.


Each Nextiva Internet fax plan includes a variety of features, such as:

  • Ability to access faxes anywhere you have an Internet connection
  • Online portal that tracks all faxed documents and usage
  • Send and receive faxes with mobile device

Supported and Certified PBX Systems

8x8 claims that their SIP trunking service supports virtually any IP-PBX, including Asterisk, Switchvox, and Trixbox.  Additionally, this SIP trunking provider is certified for the Microsoft Response Point phone system.

Nextiva supports all of the systems listed above, as well as Cisco, 3CX, Elastix, Alltel, and FreePBX.  Nextiva is also certified for several phone systems, including Panasonic, ZULTYS, and Avaya.

Pros and Cons

8x8’s SIP trunking service offers many useful features.  One of the key benefits, free and unlimited calling between 8x8 extensions, makes it a great fit for larger companies with multiple branches and remote workers.

Another plus for larger businesses is 8x8's unlimited concurrent calling feature.  Because this default setting allows you to make as many simultaneous calls as you need, you won’t have to pay for additional capacity.

Nextiva’s SIP trunking service also provides a great deal of functionality.  With a flat monthly rate, you can easily predict and manage your spending.  Plus, Nextiva offers unlimited calling bundles in the United States and Canada, so you can manage how much you spend on calling minutes as well.

Conclusion: Choosing a SIP Trunking Provider

So, which SIP trunk provider is right for your business?

Both 8x8 and Nextiva are strong contenders, so it really depends.  8x8, Nextiva, and all SIP trunking providers have pros and cons.  In order to make the best choice for your business, take the time to review your individual requirements, and determine which provider meets your needs.

As you compile a list of your business's telephony needs, you may find it helpful to keep the following questions in mind:

• What is the maximum number of simultaneous calls (both incoming and outgoing) that you need to support?
• Do you have a standard PBX or an IP-PBX?
• How many incoming phone numbers does your business need?

With the answers to these questions in hand, you’ll be able to compare and contrast SIP trunking providers and determine which one is best for you.