Ask HN: how to verify users identity (background check)?

[rush-tea]

As I am building my marketplace startup, I would need to verify the identity of my user before I send them ACH for their payment.

I am curious to find out what and how you would use in term of verifying your user identity. I understand like airbnb is using offline identity (passport or driver license), taskrabbits are using background check (sterling info systems), I think Zaarly is also using some background check as well.

if using background check firms, who would you recommend that is startup friendly in term of integration and cost?

Thanks.

[lifeguard]

One trick I have seen online merchants use is to credit a prospective customer's account a small sum of money, like $1.16. Then call the customer and ask them to tell merchant the amount that was added. If the customer has full access to the account, customer can answer the question. If the credit card is stolen, the customer will not know the amount merchant credited.