Number Blocks and Safety Valve Petitions
Requests for blocks of telephone numbers should be addressed to the North American Numbering Plan Administrator. If Somos denies a request, the provider may appeal that denial to the Public Service Commission of Wisconsin. Such appeals are typically called Safety Valve petitions.
A Safety Valve petition must be filed electronically via the Commission’s
Electronic Records Filing (ERF) system.
Safety Valve petitions must include the following:
- A summary of the petition, identifying the customer, what numbers are needed, the reason the numbers are needed, and any deadlines faced by the customer.
- A detailed description of the customer’s need for numbers, including:
- The numbers being requested,
- The reasons for the request,
- The customer’s projected timeframe and applicable deadlines.
- An explanation regarding any dial access code conflicts or restrictions due to customer needs, and whether those needs are technical or merely customer preference.
- Any applicable dialing restrictions or requirements.
- An explanation of the anticipated expenses and/or problems that the customer may incur if the safety valve is denied.
- A detailed explanation of why additional telephone numbers are needed and why they cannot be provided from existing inventory.
- A description of the actions the provider has taken to acquire the requested numbers, including why the numbering request can’t be satisfied with its current inventory of numbers and what other avenues were explored.
- An overview of the quantity of telephone numbers currently in service as well as the anticipated date that all of the new numbers will be in service if the safety valve is approved.
- An overview of the procedures the provider uses to preserve number inventory, including the steps the provider takes to preserve contiguous blocks within available numbering resources.
- An explanation of what will be done with any existing numbers currently in use by the customer. If the customer is moving and requires a number change at the new address, explain what will happen to the numbers currently in service. If the provider will not return those number to the pool, explain why not, and include the mean time to exhaust and percentage utilization for that exchange.
- Clarification of any unusual circumstances which should be considered by Commission staff.
The following documents should be provided as attachments to the filing:
- The customer request letter. The letter should include the business name and contact person’s name, title, phone number and email address.
- The thousands-block application form (Part 1A),
- The provider’s months to exhaust and utilization worksheets (MTE worksheet), and
- The PA denial (Part 3).
Questions or comments about Safety Valve petitions should be addressed to Peter Jahn at 608-267-2338, or via email at
Questions about using the Electronic Records Filing System should be directed to the Records Management unit at (608)261-8524 or via email at