SIP Trunk in Costa Rica lets businesses make and receive calls over the internet, with local numbers and without traditional physical lines. It is the foundation of modern telephony for offices, call centers and remote teams in the country.
This guide is specific to Costa Rica: local numbering, porting and local pricing. If you would rather start with the concept, read What is a SIP Trunk and how it works.
What is a SIP Trunk
A SIP Trunk is a virtual trunk that connects your phone system (PBX) to the public network over the internet, using the SIP protocol. Instead of contracting E1 or analog lines, calls travel as data. For the technical detail, read what a SIP Trunk is and how it works.
Local Costa Rica numbers
With a SIP Trunk you can have geographic Costa Rica numbers (for example in the 4300-xxxx range) so your customers call you at a local rate, plus United States and toll-free numbers. This projects closeness and trust no matter where your offices physically are.
Number porting
If you already have numbers with another carrier, in most cases you can keep them through porting, subject to carrier availability. This way you move to IP telephony without losing your known number or reprinting materials.
Savings over traditional lines
SIP Trunk lowers the cost per channel and per minute versus physical lines. You pay for concurrent channels and usage, and it scales with your real demand, with no construction or costly equipment.
- Lower fixed cost: removes physical lines and trunks.
- Scalable: add or remove channels in minutes.
- Continuity: backup routes and failover if the link fails.
Which phone systems it works with
SIP Trunk is compatible with Asterisk, FreePBX, 3CX and most physical, virtual or cloud IP PBXs. If you already have a system, you can modernize just the connectivity; if you prefer a complete solution with no hardware, see business IP telephony or the IP-PBX system plans.
What you need to get a SIP Trunk in Costa Rica
- A SIP-compatible phone system (or a managed system).
- Define how many concurrent channels you need.
- Local, United States or toll-free numbers as needed.
- Security configuration, codecs and call testing.
TelHarbor provisions, configures and monitors the trunk, with local support. Learn about the service on the SIP Trunk page or request a quote.
How many channels to buy
A SIP Trunk is bought by concurrent channel: how many calls you can have at the same time. The typical mistake is asking for one channel per employee, which means overpaying.
Practical reference: in a normal office, roughly 1 channel per 3 to 5 users; in a contact center, close to one per agent plus a margin. If unsure, look at how many simultaneous calls you reached in last month's peak hour and add 20 %.
Getting it wrong is cheap: channels are added or removed in minutes, with no cabling and no site visit. Exactly the opposite of physical lines.
What to check on your network before installing
- Bandwidth: around 100 kbps per call each way. Ten simultaneous calls is about 1 Mbps.
- Stability: latency, jitter and packet loss. That is what decides whether it sounds good; a fast but unstable link sounds worse than a slow, steady one.
- Voice prioritisation (QoS) on the router, so a large download does not chop a call.
- NAT and firewall configured properly: the classic cause of "the call connects but there is no audio".
- Link backup: if the operation depends on the phone, a second internet link or a divert route is worth having.
Security: toll fraud is real
A poorly protected trunk is a surprise invoice. Attacks hunt for weak credentials to place calls to expensive destinations, typically overnight or at weekends when nobody is watching. The basic defences:
- Strong credentials and registration only from authorised IPs.
- Encrypted signalling with TLS and audio with SRTP.
- Spend and channel caps, so any abuse hits a ceiling quickly.
- Blocking international destinations your company never dials.
- Unusual-usage alerts, which is what actually catches the problem in time.
What commissioning looks like
- Your PBX and link are reviewed, and the channel count is agreed.
- The trunk is provisioned with temporary numbers and tested: inbound, outbound, DTMF, transfers and caller ID.
- Codecs, NAT and voice prioritisation are tuned.
- The old number is forwarded to the new trunk while porting is filed.
- The port runs in a low-traffic window and the forward is removed.
The whole testing period happens without touching your existing numbers, so the operation is never interrupted.
What to ask before signing
- Are the numbers in my company's name and portable if I leave?
- Is there an alternate route if the primary fails?
- How is it billed: per channel, per minute or as a bundle?
- Is there a configurable spend cap?
- Who do I talk to if there is an audio problem mid-morning?
Frequently asked questions
Can I have local Costa Rica numbers?
Yes. Subject to availability you can enable geographic Costa Rica numbers, plus United States and toll-free numbers.
Can I keep my current number?
In most cases yes, through number porting subject to carrier availability.
Does it work with my FreePBX or Asterisk system?
Yes. SIP Trunk works with Asterisk, FreePBX, 3CX and most SIP-compatible IP systems.
How much does a SIP Trunk cost?
You pay for channels and usage. See an option with SIP Trunk included in the plans or request a tailored quote.
How many channels do I need?
In a normal office, roughly 1 per 3 to 5 users; in a contact center, close to one per agent. Last month peak hour is the best reference.
How much bandwidth does it use?
Around 100 kbps per call each way. What is critical is link stability, not the headline speed.
How do I protect against toll fraud?
Strong credentials, IP-based registration, TLS/SRTP encryption, spend caps, blocking destinations you never use, and unusual-usage alerts.
Is my operation interrupted during installation?
No. Everything is tested with temporary numbers and your existing numbers are only touched at the end, during porting, in a low-traffic window.