"How much is the consultation fee?"

Translation: 咨询的费用是多少？

[Nic.chu]

In a business context, 諮詢費 should be translated as consultancy fee in my opinion. Consultation fee sounds more like a charge for seeing a doctor. Any thoughts?

[crush]

I've added consulting fee and consultancy fee, though in my experience consulting fee/consultation fee are much more common. Thanks for the feedback!

[Semeltin]

Nice to see a reply of a mod.

[PeaceJoyPancakes]

Agreed.

[tgaertig]

Is the 是 necessary?

[nashih]

Colloquially, not. Linguistically, not sure.

[KX3.]

It sounds a bit abrupt and rude without it.

[IsaacDavis179920]

咨询费多少 is what I would feel inclined to use in conversation. The "是" feels a little stiff, but this is a business unit, so perhaps the formality is by design.