From Wikipedia

You can use this form to block editing access and account creation from individual accounts or IPs in accordance with the blocking policy.

Please remember to include an informative reason for blocking. When using the pull-down menu, please also elaborate on the following line whenever helpful (citing relevant policy pages, sock puppet accounts, the nature of the disruption, Arbitration Committee rulings, etc.). Use civil, appropriate, and professional diction. Keep in mind that the block message will be very visible when volunteers try to edit Wikipedia.

  • When blocking legitimate bot accounts, please ensure that you disable autoblocks as this can block the bot owner.

Related pages: Block log, List of active blocks and rangeblocks, Unblock form, Rangeblock helper, Autoblock check, Tor check, List of block message templates.

IP addresses

  • In general: Most IP addresses should not be blocked for more than a few days, as they may be reassigned to innocent users. Only in rare cases should IPs be blocked indefinitely. For detailed information on blocking IP addresses, please see Wikipedia:Blocking IP addresses.
  • Shared IPs: Before blocking an IP address with a long history of vandalism, please check if it is a shared proxy server or part of a dynamic IP address pool.
    See here for details on how to identify and tag such addresses. When blocking, please ensure that Block anonymous users only is checked to limit collateral damage to innocent users and consider reporting the IP to Wikipedia:WikiProject on XFFs.
  • Blocks of governmental IP ranges: If you block any IP in the ranges listed on the right under "Sensitive IP addresses", you must notify the Wikimedia Foundation Communications Committee immediately (see contact instructions there or use the notifications page). These ranges are allocated to major governmental organizations; blocks of these organizations have political and public relations implications of which the Foundation's press relations team must be aware. Avoid long blocks of these addresses, and be especially careful in formulating your block messages because your block message will probably be seen and commented on by the press.