"May I help you?" or " Do you need anything?" which is more suitable in customer service?

May I help you? How can I help you today? We're here to help you? How can I assist you today?

How may I help you? Customers will be welcoming of most greetings that are warm, friendly and show genuine interest in them as customers.
It is the false, cold, matter-of-fact, insincere, pushy greetings that customers do not like and are vey suspicious of.

Rapport: is a feeling of comfort and trust between people.
It means that we can show that we are responsive and willing to help.
Points to build a rapport over the phone: Voice tone – Pace – Language – Listen actively – Concentrate – Show interest – Don't interrupt – Respond suitably – Be energetic – Speak clearly – Ask for ideas – Offer suggestions – Discover needs – Overcome objections.

Of course "May I help you"

"May I help you"

'How may I help You?' might be even better....

May i help you i better i think

Hi - While taking to customers one has to be formal, i would support 'how may i help you' customers are percious so such words mixed with politeness works wonder......

Sure May I Help You , But Don't Ask Him While You Are In His Back ! , Go To His Face And Ask Him gently

"May I help you" sounds better.
"Do you need anything" sounds as if you are being forced to help the client.
"May I help you" is more polite whereas "do you need anything" seems like a teenager being forced to work a part-time job would say it.

(May I help you) with smile, eye contact.