Europe
SIP Trunk Austria — +43 Termination & DID Numbers
Austria uses variable-length numbers, and companies often publish direct-dial extensions (Durchwahl) appended to the main number, so a valid number can be longer than you expect. Make sure your number validation accepts the extra digits.
Overview
Routing calls to Austria
Most Austria traffic we see ends in Vienna, Graz and Linz, Salzburg and Innsbruck. Each +43 prefix is mapped to at least two carriers, and we watch ASR, ACD and PDD per prefix so a degrading route is replaced before your agents notice.
Numbering in Austria is managed by RTR. We terminate to geographic, national, mobile and toll-free ranges and price each one separately on the rate sheet. Inside the country, numbers are dialled with a 0 trunk prefix. Strip it before you send the call, and send 43 followed by the national number.
For inbound numbers in Austria, plan on paperwork: proof of address and company or identity documents are usually required before a DID goes live. Termination needs no documents beyond normal account checks.
What you get
What you get in Austria
One account and one balance, with the same SBCs for termination and inbound numbers.
CLI route tier
Caller ID delivered end to end on +43 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 +43 prefix is mapped to more than one carrier. Failed attempts move to the next one automatically.
Number formats
How to dial Austria from your PBX
Send E.164 digits. The sample number below shows the format only.
| Format | Example | Notes |
|---|---|---|
| International (E.164) | +43 1 234 5678 | How the number is written and stored. |
| Sent from your PBX | 4312345678 | E.164 digits with no plus, prefixed by your tech prefix if your account uses one. |
| With 00 exit code | 00 43 1 234 5678 | Accepted on the trunk. We normalise it to E.164. |
| National format | 01 234 5678 | Dialled inside Austria. Strip the trunk prefix before sending. |
Compliance
Austria rules to know
What applies before your first call or your first DID goes live.
Compliance box
- Regulator
- RTR
- 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 Austria routes
- 01
DACH customer service with Vienna 01 numbers alongside German lines
- 02
Companies publishing direct-dial extensions on a single Austrian range
- 03
0800 freephone lines for national retail and insurance
Setup
Start calling Austria 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 +43
Send 43 + national number in E.164 and check the CDR for your first test call.
Further reading: ASR and ACD Explained: How to Judge a VoIP Route
FAQ
Austria SIP trunk questions
Why are some Austrian numbers longer than others?
Austria has variable-length numbering, and extensions can be appended directly to a company's main number.
What is the Vienna area code?
01 nationally, so a Vienna number is +43 1 followed by the subscriber number.
Who regulates Austrian telecoms?
RTR (Rundfunk und Telekom Regulierungs-GmbH) handles numbering administration.
Do Austrian DIDs need an address?
Usually yes, plus identity or company documents.
