Please let me/us know your emergency contact number.
How can I get a contact with you in case of an emergency?
Please let me/us know your emergency contact number.
緊急連絡先を教えてください。
How can I get a contact with you in case of an emergency?
緊急時はどうすれば連絡できますか？
緊急時が "in case of an emergency"です。
緊急連絡先は、"emergency contact number" になります。
Could I please have your emergency contact information?
When asking someone about their emergency contact number, you are essentially asking them for the name and number of their next of kin. The next of kin is the person who you should contact if that person needs help. If you want the information of that person, you could ask, "How can I contact you in case of an emergency".
「emergency contact number（緊急連絡先）」を尋ねるということは、つまりその人の「next of kin（最近親者）」の名前と連絡先を聞いているということです。「next of kin」は、その人に何かあった時に連絡する人のことです。その人の連絡先が知りたいなら、例えば：
"How can I contact you in case of an emergency?"
（緊急時はどのように連絡を取ったらいいですか）
How can I get in touch with you in case of an emergency?
May I have your emergency contact information?
The first question is a way of asking for someone's emergency contact information while giving a reason for it, as in, as in an emergency might happen and you need to call this person.
The second question is a more polite way to ask for someone's contact information. The word "May" always signifies politeness.
Hope this helps!
Please could i have your emergency contact details
Please could i have your emergency contact information
Please let me have your emergency contact number
You would say 'please' in front to be polite, you could use either details/information or number to ask for the information you require/want
'To let me have' means to be given by someone
So the best way to say it is 'Please let me have your emergency contact number'
文頭に「please」を付けると丁寧になります。
「情報」は「details」「information」「number」で表せます。
「let me have」は「与えて欲しい」という意味です。
ですから、一番いい言い方としては：
'Please let me have your emergency contact number.'
（緊急連絡先を教えてください）
日本 
アメリカ合衆国 
カナダ 
イギリス 
