Asking these questions should give you an idea of what it will be like working with them. Your relationship with your umbrella company is important, so don't make your decision lightly.
How much do they charge? And are there any extra charges?
How many clients on their books?
Can you claim business expenses? Do you need receipts?
Are insurances included in the price? What are they and for how much?
How quickly will you be paid after sending over your timesheet?
Will you have your own account manager?
Is there a formal complaints procedure?
What are their opening hours? Does this suit you, if you need to call them?
Can you leave them at any time without having to pay a penalty?
What happens to your account when your contract ends?
Through these questions you will find answers that will guide you to the right direction