0300 and 0303 numbers: definition and a practical example
Short answer: 0300 and 0303 numbers are Brazilian nationwide shared-cost access codes, where the cost of the call is split between the caller and the number's subscriber, under Anatel's numbering plan.
In Portuguese: Números 0300 e 0303
What are 0300 and 0303 numbers?
They are nationwide shared-cost access codes: the cost of the call is split between the caller and the number’s subscriber. The rule is in Anatel Resolution No. 749/2022 (Resolução Anatel nº 749/2022), art. 18, the same rule that makes 0800 free for the caller.
The two serve different purposes. 0300 is a number for receiving calls: customer service, support and information lines, where a company wants a single nationwide number without bearing the whole cost as it would with 0800. 0303 identifies high-volume callers. Under Anatel Act No. 12,712/2024 (Ato Anatel nº 12.712/2024), it is mandatory for anyone who makes more than 10,000 calls on at least one day of the month, as in telemarketing, debt collection and fundraising. The number appears on the screen of the person receiving the call.
Like 0800, a 0300 number is translated by the carrier’s network to a real destination, usually one of the company’s trunks, which delivers the call to the PBX and the IVR. Routing at the carrier is a point of failure that PBX monitoring does not see.
In practice
A comparison of the most common access numbers:
| Number | Who pays | Typical use |
|---|---|---|
| 0800 | Subscriber | SAC (the customer-service channel Brazilian law regulates), ombudsman, support |
| 0300 | Shared cost | Customer service on a nationwide number |
| 0303 | Shared cost | Mass calling: telemarketing, debt collection, fundraising |
| 4004, 4003, 3003 | The caller, usually as a local call, according to the carriers | Single nationwide number |
The 4004, 4003 and 3003 numbers are not a category in Anatel’s numbering plan; see 4004, 4003 and 3003 numbers. Choosing between them comes down to who the company wants to bear the cost of the call and whether the number will receive calls or make them.
How Monitor uses this
Any dialable number can be monitored, including 0300 and 0303. The test dials the number itself, just as a customer would, and goes through the carrier’s translation, the trunk and the IVR, testing the full path the customer uses. See toll-free and IVR monitoring.
Frequently asked questions
Who is required to use 0303?
Under Anatel Act No. 12,712/2024 (Ato Anatel nº 12.712/2024), anyone who makes more than 10,000 calls on at least one day of the month must use the 0303 code. That covers activities such as telemarketing, debt collection and fundraising. With 0303 on the screen, the person receiving the call knows up front what kind of call it is and can decide whether to pick up.
What is the difference between 0300 and 0800?
Who pays. With 0800 (toll-free), the call is free for the caller and the subscriber pays everything. With 0300, the cost is shared between the caller and the subscriber, under Anatel Resolution No. 749/2022 (Resolução Anatel nº 749/2022), art. 18. Both are nationwide numbers that the carrier routes to the company's real destination, and both can fail in routing without the PBX noticing.