By NoCall Team

How to find out who is calling from an unknown number

Unknown calls are common in Spain. Before you call back, check whether other people have already identified the number. The NoCall community has collected more than 0 reports on Spanish phone numbers.

1. Search the number on NoCall

The fastest way to understand a call. NoCall maintains a database with more than 30.956 numbers flagged by the community. For each number you can see:

  • Risk score — from 0 (safer) to 100 (high risk).
  • Category — spam, telemarketing, scam, debt collection, surveys.
  • Carrier and line type — mobile, landline, premium-rate.
  • Comments — what others experienced from the same caller.
  • Search interest — how often the number has been looked up recently.

2. Read the prefix

The prefix tells you a lot about the kind of line:

6XX, 7XXMobile
91X–95XLandline (by area: 91 Madrid, 93 Barcelona, 95 Seville, and so on)
800, 900Toll-free numbers (companies and support lines)
803–807Premium / special-rate services — high per-minute cost
901, 902Shared-cost numbers (extra charges when you call back)

On NoCall you can browse numbers for a whole prefix. For example, numbers starting with 911 or numbers starting with 900.

3. Check whether it matches a known company

Many businesses publish their official numbers online. If the caller ID matches your bank or a provider, it might be legitimate — but scammers can spoof well-known numbers. When in doubt, hang up and dial the number from the company’s official website or contract.

4. Do not call back blindly

If you find nothing and do not recognise the number, do not return the call. Some premium prefixes (803, 806, 807) can be very expensive. Genuine callers will try again or reach you another way.

5. Automate protection

With the NoCall app, numbers that are already reported as spam can be blocked automatically. You do not have to research every unknown caller manually — the app helps shield you from more than 30.956 known spam numbers.

Had a call from an unknown number?

Look it up in our database with more than 0 community reports:

Perguntas frequentes

Como posso descobrir quem ligou de um número desconhecido?+

Pesquise o número na NoCall — mais de 0 denúncias reais de utilizadores ajudam-no a distinguir spam, telemarketing ou uma fraude. Também pode verificar o prefixo para saber o tipo de linha e a operadora.

O que significam os prefixos telefónicos espanhóis?+

6XX e 7XX são telemóveis, 9XX são fixos (por área), 800 e 900 são gratuitos, 803/806/807 são de tarifa premium com custo elevado, e 901/902 acrescentam encargos extra quando liga.

É seguro ligar de volta para um número desconhecido?+

Não sem verificar primeiro. Alguns números de tarifa premium cobram taxas elevadas quando devolve a chamada. Pesquise sempre o número na NoCall antes de ligar de volta.

Pesquise um número de telefone ou um nome de empresa (Itaú, Vivo e Claro...) para verificar se foi denunciado como spam.

Como ver quem está a ligar de um número desconhecido | NoCall