If you decide to contract with us, as well as carry out any modification of the contract, you must fill out the online form at www.lumisa.es/contrata-ahora/en and once done, confirm with an online signature.
You should have available:
Email, which you will receive to access the online signature.
Mobile phone, where a confirmation PIN will be sent.
The steps to follow can also be found in the article "How to sign a contract online in three simple steps."