Glossary · Carriers and wholesale
Call termination
In one sentence
Call termination is the final leg of a phone call: carrying it across the called person's network, which charges the originating carrier a termination fee. The cost depends on the country, the line type (landline or mobile) and the route used.
Also known as : call termination · voice termination · termination rates · termination rate · wholesale voice termination
What is call termination?
When your business calls a supplier in Lagos, the call crosses several networks. Your carrier takes it to an interconnection point, one or more transit carriers may relay it, and the supplier’s Nigerian operator delivers it to their phone. That final leg is call termination, and it is the leg that gets billed: the destination operator charges whoever hands it the call a per-minute termination fee.
In carrier language you “terminate traffic” to a country. A wholesale termination provider lets other carriers, CPaaS platforms and integrators send calls to destinations they do not reach directly.
How it works
- The originating carrier receives the call from its customer, for example over a SIP trunk.
- Without a direct agreement with the destination operator, it hands the call to a wholesale transit carrier.
- The transit carrier picks a route by price and measured quality: answer-seizure ratio (ASR), average call duration, post-dial delay.
- The destination operator terminates the call on its network and bills the termination fee, which passes back down the chain to the end customer.
Routes are not equal. A CLI route keeps the caller ID intact; cheaper grey routes lose or replace it, so fewer people pick up. Caller authentication frameworks such as STIR/SHAKEN and Ofcom’s rules on blocking spoofed numbers make the origin of traffic increasingly visible.
Within the EU, termination rates for fixed and mobile calls are capped by a single EU-wide maximum. Outside it, each country sets its own rules, and the gap between landline and mobile rates can be wide.
Example
A logistics broker in Felixstowe calls drivers and depots across West Africa every day. Calls went through its provider’s default international route: many failed, and drivers saw random foreign numbers they would not answer. The broker’s IT partner, which also runs voice for other clients, buys wholesale termination with CLI routes to Nigeria and Ghana. Calls now show the broker’s number, more of them are answered, and the cost per destination is known in advance.
Call termination at Universal Telecom
Our wholesale page covers SIP trunking and local numbering for carriers, ITSPs and integrators, with the country list on the coverage page. For a business rather than a carrier, per-minute prices by country are on the call rates page.
Frequently asked questions
What is a CLI route?
A route that delivers the caller's number intact to the person being called. Non-CLI or 'grey' routes are cheaper but strip or alter the number, which lowers answer rates and can breach rules against number spoofing.
What do ASR and ACD mean in wholesale voice?
ASR (answer-seizure ratio) is the share of call attempts that are answered. In wholesale reporting, ACD usually means average call duration. Low ASR or very short ACD on a route are classic signs of poor quality or fraud.
Who sets termination rates?
The operator that owns the destination network, within limits set by its regulator. In the EU, fixed and mobile termination rates are capped by a single maximum rate set by the European Commission; in the UK, Ofcom regulates them.
Related terms
- BYOC (bring your own carrier)
BYOC (bring your own carrier) means connecting a communications platform, such as Microsoft Teams, a cloud contact centre or a voice-agent platform, to the carrier of your choice over a SIP trunk, instead of using the telephony the platform sells.
- SIP trunk
A SIP trunk is a voice-over-IP connection between a business phone system and a carrier. It replaces ISDN lines and carries calls and numbers over your internet connection.
- Caller ID (CLI)
Caller ID, or CLI (calling line identification), is the caller's number passed through the network and shown to the person called. A business may only present a valid number that it is entitled to use.
- STIR/SHAKEN
STIR/SHAKEN is a set of standards that lets the originating carrier digitally sign a call to vouch that the caller is entitled to the number shown, so terminating carriers can detect spoofed caller ID.
- CPaaS
CPaaS (communications platform as a service) is a cloud service that provides communication building blocks, such as voice calls, SMS, WhatsApp, video and phone numbers, as APIs that developers embed in their own applications.
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