Is it permissible to lie at work and to contact competing companies as a customer to find out about their services and prices? Is this act haram (forbidden)?

Lying is forbidden by Islamic law. It is defined as reporting something contrary to its true nature, and there is a consensus among the Ummah regarding its prohibition. Therefore, if you inform competing companies of something contrary to reality, it is a lie and impermissible. However, if companies merely assume you are a customer without you explicitly stating anything contrary to reality, this is not considered lying, unless you use it to achieve something false, in which case it falls under "ma'arid" (euphemisms/allusions). "Tawriya" (double entendre) and "ta'rid" (allusion) involve using a word that appears to mean one thing, but intending another meaning different from its apparent one. If there is a preponderant benefit or an urgent need, then it is permissible. Otherwise, it is disliked (makruh), and it becomes forbidden if used to achieve something false or to deny a right.