UIFN vs. ITFS / 0800

The key difference between an ITFS (International Toll-Free Service) number and a UIFN is reachability.
While ITFS numbers work only within a single country, a UIFN can be activated across multiple countries, allowing you to advertise one single toll-free number globally.
In most regions, customers can dial your UIFN using 00 800 or +800 followed by your number.
(Refer to our product sheet and price list for region-specific dialing formats.)

Assignment & Activation

UIFN numbers are assigned by the ITU (International Telecommunication Union) directly to the end user — meaning you fully own the number.

Tellimon can help you with ITU registration or manage the entire process on your behalf with no added markup on ITU fees.

During setup, you simply select the countries where your UIFN should be active.
Activation in a country means callers in that region can reach your UIFN. As your business grows, you can easily request activation in additional countries.

Thanks to central ITU registration, no local address or presence is required, unlike many individual ITFS numbers.

Existing Numbers & Porting

If you already have a UIFN, Tellimon can:

• Fully manage your number porting

• Activate your UIFN in additional countries

• Transfer existing activations to Tellimon for unified billing and full control

We can activate your current UIFN across new regions or consolidate all existing countries into our service, giving you one provider, one invoice, and a single platform to manage everything.

UIFN Reachability

UIFN reachability depends on commercial agreements with local telecom operators.
Tellimon handles all carrier relations, ensuring this never becomes a burden for you.

In some countries, not all operators may support UIFN or may apply airtime charges to the caller. Tellimon provides full transparency and lists all known limitations or charges in our documentation and pricing.

This ensures you always have accurate, up-to-date information to guide your customers.

All Information in One Place

To make choosing between ITFS and UIFN simpler, Tellimon consolidates all commercial details, reachability information, and activation differences into a single, easy-to-compare monthly price list.

This helps you clearly evaluate the best number type for every region.

How to Get Started with UIFN

Whether you need a new UIFN, want to expand activation into more countries, or want to move your existing UIFN to Tellimon, our team is here to help.

Contact our sales team to discuss your needs, pricing, and activation options.
Together, we’ll help you choose the most effective global toll-free solution for your business.