TLDR: You must contact your business tax service (SIE) to request the invalidation of your VAT intra-Community number if you no longer carry out operations requiring this identification. No specific method (online, form, deadline) is specified by the administration.
When to request revocation
Revocation is mandatory as soon as you no longer carry out operations for which VAT intra-Community identification is required. This avoids keeping an active number unnecessarily.
Who is concerned
Any taxable person, regardless of their legal form, must carry out this procedure if they cease the activities justifying the allocation of the number.
Procedure to follow
You must contact your competent business tax service (SIE) directly. No other formality (online, standard letter, deadline) is imposed by the official texts.
Consequences of inaction
The number remains active until the invalidation request is submitted. No specific penalty is explicitly provided for its maintenance, but it may lead to unnecessary declarative obligations.
Special cases
No exceptions are mentioned for specific taxable persons (e.g., non-profit organizations, agricultural operators). The rule applies uniformly.
Evidence and supporting documents
No particular document is required for the request. The SIE relies on your declaration of cessation of the relevant operations.