Callcentric SIP Trunking

Overview

Callcentric SIP Trunking is an outbound, pay-per-minute service for businesses placing calls through SIP-based IP PBXs or gateways. It suits teams that want to use their own compatible equipment and avoid a recurring trunk fee. Its strongest case is flexible, low-commitment calling; its clearest drawback is the lack of encrypted SIP or audio transport.

Pay Per Call supports business and office use, call centers, IVR services, calling card providers, and any purpose. Calls to other Callcentric members are free, while worldwide outbound calls cost variable per-minute rates. The plan has no included minutes, so spending depends on destinations and usage.

Key features

Bring your own equipment

Callcentric says most SIP/2.0 hardware and software should work and does not confine customers to equipment it has chosen. Its compatibility FAQ names 3CX, Asterisk, freePBX, Bria, ZoIPer, and LinPhone among software users have successfully used. This broad approach can suit businesses with an existing PBX or gateway, but compatibility still depends on meeting the technical requirements: SIP 2.0, RTP over UDP, DIGEST MD5 authentication, a fixed outbound proxy, DNS SRV, and G.711 and/or G.729.

Account controls and privacy

Administrators can limit calling destinations and configure IP whitelisting globally or per extension; Callcentric also recommends complex passwords. Those controls can help restrict account use, but they do not replace encrypted call transport. Callcentric says it does not support audio or SIP communications using RTPS or SIPS. It says credentials are encrypted during REGISTER and INVITE according to SIP, and that it does not listen to calls or access users' login passwords.

Numbers and support

Business numbers are offered in the USA, Canada, and more than 35 other countries. Number porting, emergency calling, and toll-free numbers are supported. US/Canada toll-free numbers cost $3.95 setup and $3.95 per month; other US/Canada and international number prices vary by product or country. A maintained knowledge base, BYOD setup guides, and free support through trouble tickets give customers routes to help with configuration.

Pricing

Pay Per Call

The sole plan costs nothing (billed Month to month: $0.00). It is outbound-only, includes three channels, allows unlimited maximum channels, and charges $0.00 for additional channels. There are no included minutes; outbound calls incur variable per-minute charges, while calls to other Callcentric members are free. An account deposit can be as low as $5.00, and the plan has no commitment.

This structure fits businesses with variable or modest outbound use that want to avoid fixed trunk charges, especially when they make calls to other Callcentric members. It is less predictable for teams with substantial paid outbound traffic because there is no minute allowance or fixed per-minute rate in the plan. The three included channels provide a starting capacity; the stated unlimited maximum and zero additional-channel fee remove a channel charge, but do not make calling free. There is no free trial.

Platforms

Callcentric lists Android, iOS, Linux, macOS, Windows, web, extension, and self-hosted platforms. The service is intended for SIP-based IP PBXs and gateways, so check that the specific device or software meets the listed protocol and codec requirements before committing.

Who it's for

Callcentric is a sensible fit for businesses, call centers, IVR services, and calling card providers seeking outbound SIP calling with their own compatible equipment, low entry costs, and access to business numbers across multiple countries. It is a weaker choice for organizations that require encrypted SIP or audio transport, want included minutes, or need a fixed outbound calling price.

Pros and cons

Pros

• No monthly trunk fee or commitment: businesses can start without a recurring plan charge, with an account deposit as low as $5.00.
• Flexible equipment choice: Callcentric supports a range of SIP hardware and software rather than limiting customers to a short approved-device list.
• Broad number options: business numbers span the USA, Canada, and more than 35 other countries, with porting, emergency calling, and toll-free numbers supported.
• Channel cost clarity: three channels are included, with no fee for additional channels.

Cons

• No included minutes: paid outbound use is entirely variable-rate, making costs dependent on destination and call volume.
• No RTPS or SIPS: organizations that require encrypted audio or SIP communications should look elsewhere.
• Technical fit matters: devices must meet the stated SIP, transport, authentication, proxy, DNS, and codec requirements.

Alternatives

For a broader comparison, browse SIP Trunking Providers.

Choose IPComms SIP Trunking if usage-billed SIP trunking with $0 trunk and channel fees, no contract, a free plan, and a free trial better suits your priorities. Consider Callivex SIP Trunking if wholesale custom rates based on destination mix, projected volume, and traffic profile are a better fit.

Twilio Segment is a freemium product with a free plan and trial. Telnyx Text-to-Speech API offers pay-as-you-go pricing with a $0 monthly minimum and automatic tier discounts. AT&T IP Flexible Reach, BICS SIP Trunking, BT Global SIP, and Colt SIP Trunking are other options to consider.

Verdict

Choose Callcentric if you need outbound SIP trunking on your own compatible equipment, want no recurring trunk fee, and value flexible international business-number availability. Look elsewhere if encrypted SIP or audio is essential, or if included minutes or predictable outbound rates matter more than a low-commitment pay-per-minute model.