G.R. No. L-29022 May 26, 1977
PHILIPPINE LONG DISTANCE TELEPHONE CO., petitioner, vs. THE PUBLIC SERVICE COMMISSION and LORETO T. CASTILLO, respondents.

FACTS

The respondent, Loreto T. Castillo, a lawyer and licensed real estate broker, operated both his “Castillo Law Offices” and “Como Realty” from a single room in Manila. He was a subscriber to PLDT business telephone number 3-35-31, paying the authorized monthly rate of P24.00. Both business names were listed under this single number in PLDT’s directory, with Castillo paying a separate fee for the “Como Realty” listing. In 1958, PLDT notified Castillo that he must apply for a “Joint User” service and pay an additional P7.00 monthly charge for the “Como Realty” listing to be included in the new directory, asserting that his use of the single line for two distinct businesses fell under its approved joint user tariff.
The Public Service Commission (PSC) ruled in favor of Castillo, holding that PLDT could not charge the joint user rate against him. PLDT sought review, arguing it was authorized to impose such a rate in Manila and that Castillo’s dual business use of the line qualified for the charge. The PSC, however, found it unnecessary to resolve the first issue after concluding that “Como Realty” was not a proper joint user of the telephone service.

ISSUE

The primary legal issue is whether the respondent’s use of a single telephone line for his two distinct professions subjects him to PLDT’s authorized joint user service rate.

RULING

The Supreme Court affirmed the PSC’s decision, ruling that Castillo was not liable for the joint user rate. The Court first resolved the ancillary factual issue, confirming that PLDT was indeed authorized to charge a joint user rate in Manila, as this authority was not contested by the Commission. The core of the ruling, however, centered on the application of that rate to the respondent’s specific circumstances.
The Court upheld the PSC’s factual finding that Castillo conducted both businesses alone from one room, using a single telephone for which he paid the standard business line fee. PLDT’s argument was premised on a logical deduction that two businesses would generate more calls, justifying the extra charge. The Court rejected this presumption, emphasizing the settled doctrine that the PSC’s factual conclusions are binding unless unsupported by evidence. No evidence was presented to demonstrate that the confluence of legal and real estate brokerage activities in one individual inherently doubled the call volume. The Court found it inequitable to impose a joint user charge on a subscriber using one telephone for his own dual professional capacities from a single location. The proper course for PLDT was to charge only the authorized fee for a separate directory listing, which Castillo had already paid. Therefore, the assessment of the joint user rate was unjustified.