Europe
SIP Trunk Czech Republic — +420 Termination & DID Numbers
Brno and Prague have grown into Central European support hubs for software and IT services. Czech numbers are a clean nine digits with no trunk prefix: landlines start with 2 to 5 and mobiles with 6 or 7.
Overview
Routing calls to Czech Republic
Whether you are calling a desk phone in Prague or a mobile in Ostrava, Plzeň and Liberec, the call is routed by the longest matching +420 prefix and sent to the best-performing carrier for that range. When a carrier fails, the next one takes over, and the CDR shows exactly which leg carried the call.
CTU sets the Czech Republic numbering plan, and our prefix tables follow it closely. Supported number types: geographic, national, mobile and toll-free. There is no trunk prefix to strip: send 420 followed by the national number as written.
Outbound termination to Czech Republic starts as soon as your balance is topped up. Local DIDs are different: CTU rules usually require address and identity documents, which our team collects and checks before activation.
What you get
What you get in Czech Republic
One account and one balance, with the same SBCs for termination and inbound numbers.
CLI route tier
Caller ID delivered end to end on +420 calls. Use it for sales, support and any traffic where answer rates matter.Non-CLI route tier
A lower-cost tier where caller ID delivery is not guaranteed. Suitable for internal or transactional traffic that does not depend on the CLI.Number types
Geographic, National, Mobile, Toll-free. DID availability varies by range and city.Codecs
G.711a/u and G.729 on every route, G.722 and Opus where the far end supports them. T.38 for fax.Channels on demand
Concurrent call limits are set per account and raised as your traffic grows. No fixed channel bundles.Multi-carrier failover
Every +420 prefix is mapped to more than one carrier. Failed attempts move to the next one automatically.
Number formats
How to dial Czech Republic from your PBX
Send E.164 digits. The sample number below shows the format only.
| Format | Example | Notes |
|---|---|---|
| International (E.164) | +420 212 345 678 | How the number is written and stored. |
| Sent from your PBX | 420212345678 | E.164 digits with no plus, prefixed by your tech prefix if your account uses one. |
| With 00 exit code | 00 420 212 345 678 | Accepted on the trunk. We normalise it to E.164. |
| National format | 212 345 678 | Dialled inside Czech Republic. There is no trunk prefix. |
Compliance
Czech Republic rules to know
What applies before your first call or your first DID goes live.
Compliance box
- Regulator
- CTU
- Caller ID
- A valid CLI that you are entitled to use is required on CLI routes. Spoofed or unallocated numbers are blocked.
- DID KYC
- Usually required
- Note
- Geographic DIDs usually need a local address or proof of presence in the country.
Rules change — our team confirms current requirements before activation.
Use cases
Who uses Czech Republic routes
- 01
IT service desks in Brno and Prague supporting customers across the EU
- 02
Czech and Slovak language customer care from one location
- 03
800 freephone numbers for national hotlines
Setup
Start calling Czech Republic in 3 steps
- 01
Top up $200
Open a prepaid account and add balance by USDT (TRC20), BTC or card. - 02
Add your trunk
Whitelist your PBX IP or create digest credentials, then point your outbound route at our SBC. - 03
Dial +420
Send 420 + national number in E.164 and check the CDR for your first test call.
Further reading: SIP Error Codes 401, 403, 404, 408, 480, 486, 503: Causes and Fixes
FAQ
Czech Republic SIP trunk questions
How are Czech numbers structured?
Nine digits with no trunk prefix. Prague numbers start with 2 and mobiles with 6 or 7.
Who regulates Czech telecoms?
CTU (Czech Telecommunication Office).
Do Czech DIDs need documents?
Usually yes: a local address and company (IČO) or ID details.
How do I dial a Prague number from the trunk?
Send 420 followed by the 9-digit number.
