。
May I have your phone number, please?
Literal
That-side-honorific [genitive-の] honorific-phone-number [object-を] receive-can [polite-question-ますか]?
Several keigo features. そちら様 is an extremely polite second-person form: そちら ('that direction/that side') + 様 (honorific suffix). お電話番号 has the honorific お prefix on the listener's possession. いただける is the potential of いただく (humble form of もらう, 'to receive') — '[I] can humbly receive.' The whole construction is the standard polite-business way to ask for someone's contact info.