47 CFR § 64.704 - Call blocking prohibited.
(a) Each aggregator shall ensure that each of its telephones presubscribed to a provider of operator services allows the consumer to use “800” and “950” access code numbers to obtain access to the provider of operator services desired by the consumer.
(b) Each provider of operator services shall:
(1) Ensure, by contract or tariff, that each aggregator for which such provider is the presubscribed provider of operator services is in compliance with the requirements of paragraphs (a) and (c) of this section; and
(2) Withhold payment (on a location-by-location basis) of any compensation, including commissions, to aggregators if such provider reasonably believes that the aggregator is blocking access to interstate common carriers in violation of paragraphs (a) or (c) of this section.
(c) Each aggregator shall, by the earliest applicable date set forth in this paragraph, ensure that any of its equipment presubscribed to a provider of operator services allows the consumer to use equal access codes to obtain access to the consumer's desired provider of operator services.
(1) Each pay telephone shall, within six (6) months of the effective date of this paragraph, allow the consumer to use equal access codes to obtain access to the consumer's desired provider of operator services.
(2) All equipment that is technologically capable of identifying the dialing of an equal access code followed by any sequence of numbers that will result in billing to the originating telephone and that is technologically capable of blocking access through such dialing sequences without blocking access through other dialing sequences involving equal access codes, shall, within six (6) months of the effective date of this paragraph or upon installation, whichever is sooner, allow the consumer to use equal access codes to obtain access to the consumer's desired provider of operator services.
(3) All equipment or software that is manufactured or imported on or after April 17, 1992, and installed by any aggregator shall, immediately upon installation by the aggregator, allow the consumer to use equal access codes to obtain access to the consumer's desired provider of operator services.
(4) All equipment that can be modified at a cost of no more than $15.00 per line to be technologically capable of identifying the dialing of an equal access code followed by any sequence of numbers that will result in billing to the originating telephone and to be technologically capable of blocking access through such dialing sequences without blocking access through other dialing sequences involving equal access codes, shall, within eighteen (18) months of the effective date of this paragraph, allow the consumer to use equal access codes to obtain access to the consumer's desired provider of operator services.
(5) All equipment not included in paragraphs (c)(1), (c)(2), (c)(3), or (c)(4) of this section shall, no later than April 17, 1997, allow the consumer to use equal access codes to obtain access to the consumer's desired provider of operator services.
(6) This paragraph does not apply to the use by consumers of equal access code dialing sequences that result in billing to the originating telephone.
(d) All providers of operator services, except those employing a store-and-forward device that serves only consumers at the location of the device, shall establish an “800” or “950” access code number within six (6) months of the effective date of this paragraph.
(e) The requirements of this section shall not apply to CMRS aggregators and providers of CMRS operator services.