Trusting Sellers with Confidential Information

[woodubend]

I am new to Fiverr and am about to embark on a contract with a seller. They require login access to both my website and Quickbooks account. 

How do I know whether I can trust them with this confidential information? Is there a policy (I did a cursory check but couldn't find one) I can reference?

[atulcodex]

1 hour ago, woodubend said:

I am new to Fiverr and am about to embark on a contract with a seller. They require login access to both my website and Quickbooks account. 

How do I know whether I can trust them with this confidential information? Is there a policy (I did a cursory check but couldn't find one) I can reference?

Some software allows to create user in same account, check in your software or web app may be they allow?