Business Phone Systems

Basics of choosing your company’s customer service number

Enreach 08/02/2024
Clock icon 3 min
Level: Beginner

Under the current Spanish Customer Service Law, 900 lines are mandatory for all businesses that provide essential services to the public.

But what if your business doesn’t fall into this category? If you’re not sure which number is best for your customer service, this article will give you all the alternatives, with their pros and cons.


  • Customer willingness to call: high
  • Coverage: national
  • Brand image: professional, approachable
  • Cost to the customer: free

With a toll-free main number, your company will receive a high volume of simultaneous calls. Customers who know it is free will use it without hesitation.

They are also good for companies that do not want to be visible on a map and want to project a more professional image without losing contact with their customers.

It’s important to note, however, that calls made from these numbers will cost you twice, as you’ll have to pay both to make the call and to receive the answer.

901 & 902 LINES

  • Customer willingness to call: low
  • Coverage: national
  • Brand image: professional, inaccessible
  • Cost to the customer: high

The 901 (shared cost) and 902 (national rate) numbers cost customers money. This makes them more reluctant to dial them, resulting in a much lower volume of incoming calls.

Like the previous ones, they are used by companies that do not want to have a recognisable location and, in addition to projecting professionalism, want to receive few calls.

This type of number isn’t usually used for outbound calls either, for the same reason: customers wouldn’t answer them because of the high cost.


  • Customer willingness to call: high
  • Coverage: local
  • Brand image: local
  • Cost to the customer: free in most cases, depending on the customer’s contract tariff.

Geographical or local numbers represent proximity and familiarity to the customer as they use the prefix of the province.

Although they do not project the same corporate image as 900 numbers, they do not incur additional outbound call charges.

For companies with customers spread across the country (or the world), the strategic decision is whether to standardise numbers or, conversely, to keep their local main numbers.


  • Customer willingness to call: high
  • Coverage: local / national
  • Brand image: freelancers, individuals
  • Cost to the customer: free in most cases, depending on the customer’s contract tariff.

Mobile numbering is increasingly used at corporate level, although it is usually associated with freelancers.

When people receive a call from a mobile phone, they usually assume it’s someone they know, so it can be frustrating for customers if it’s a business.

If you still want to use a mobile line for your customer service, be aware that you can only take two incoming calls at the same time, which limits your ability to handle a high volume of calls.


As we have seen, the choice of alternative numbering for customer service depends on the volume of calls you receive, the number of calls you make and the brand image you wish to project.

As a Tier 1 network operator, which means we provide the fastest and most reliable phone lines, we offer all types of numbering for businesses.

Whichever numbering you choose, you’ll have an online control panel to monitor service levels in real time.

If you later want your business number to have a welcome messageprioritised call queues or call transfer rules, we also offer a virtual switchboard from which you can configure even the smallest detail.

In addition to these advanced features, our switchboard also includes internal communication channels, allowing you to chatcall and video call for free, share all types of files and integrate with GoogleTeams and over 100 CRMs.

Are you considering hiring a numbering service for your business, but aren’t sure which is the best option? Contact our team of experts for a personalised consultation. Call us now on +34 900 670 750 or use the chat below.

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