The contractual relationship between the consumer and the telephone company should be spelled out in a document that specifies the kind of service that is provided and the current table of rates for services. The document signed by the two sides show side the address of each, the duration of the contract, and how and why the contract can be rescinded.

General terms of the contract
Furthermore, the contract must include a long list of terms that cannot be left up to the whim of the two sides. These include the conditions for maintenance of the telephone line, how billing is done, quality levels, compensation mechanisms in the event the quality levels advertised do not meet the standards spelled out in the contract, procedures deriving from non-payment of bills, ways to resolve complaints (both in Consumer Arbitration Panels or the Secretariat of Telecommunications and the Information Society), procedures to follow for exercising rights to access, opposition, rectification, restriction and cancellation with regard to the personal data of the customer and the conditions under which the telephone company can require payment of a deposit.
 
Spanish law says that in general, telephone contracts - both fixed-line and mobile - should be governed by exactness, clarity and simplicity in their wording, with the possibility of direction comprehension, without the need to send texts or documents that are not provided before the contract is signed or at the same time.
 
The rights and obligations that must exist in contracts should include cases of voluntary rescinding of the contract, temporary suspension of the service, billing for services provided and itemised cost of calls, among others.
 
In theory, contracts last indefinitely, although the two sides can set a minimum period. If the customer decides to suspend the contract, he or she must warn the service provider 15 days in advance and not forget to turn in whatever telephone headsets they might have rented.

Suspension of service 
As it is easy to imagine, the failure to pay bills or their late payment can be a motive for service to be suspended. For the company to take this step, the customer must be more than one month behind in their payments. Once the customer has been warned, the company must wait 15 days before suspending the service. On the other hand, if the non-payment persists for three months or more, the service can be cut off for good and the contract suspended.