The answer differs from case to case.
Sometimes the legislator wanted to protect all parties having concluded a contract with an operator: in that case the term “subscriber” was used. This is for instance the case for number portability or the right to terminate a contract for free when the operator proposes modifications that are not in favour of the user.
In other cases the legislator wanted to only protect the parties having a considerably weaker position than the operator.
At other times the legislator wished mainly to protect or inform the consumers. These are the persons asking or using a telecommunications service merely for private ends.The tariff simulator for instance deals with the tariff plans the operators sell to consumers. Another example: the right to switch tariff plans with the same operator at least once a year, for free, is only applicable to consumers.
Protection of consumers, self-employed and small companies
In some cases, the legislator wants to protect the self-employed and small companies in addition to the consumers.
The number of employees in the company may be important. For instance, to benefit from the termination rules applicable to consumers, the self-employed and small companies must have “a maximum of 9 employees”. The same goes for benefitting from the basic detailed invoice (this invoice must include among other things information on the duration of the subscribed contracts and the absence of contract termination fees).
Other criteria may be used for some other rules and rights. If you are a microenterprise (maximum 9 employees), a small enterprise (yearly average of maximum 49 employees), a non-profit micro-organisation (non-profit organisation or foundation with a yearly average of maximum 9 employees), or a small non-profit organisation (non-profit organisation, NGO or foundation with a yearly average of maximum 49 employees), certain protection rules are applicable by default, but you can explicitly and freely accept not to benefit from it at the time of conclusion of the contract. For instance, exceeding the maximum 24-month contract duration in exchange for a cheaper price. Or waiving the right to receive a contract summary before the conclusion of the contract.
Large companies (multinationals, hospitals, etc.) are not concerned by these protection measures, unlike the limited company of a baker or butcher around the corner having a contract including two telephone lines with corresponding numbers.
In other cases it matters whether the small business user subscribed to a tariff plan for consumers. The limited company of the baker or butcher around the corner who uses his private tariff plan for his business (as well) will automatically be informed when he exceeds his package.