Very low volume credit checks - any suggestions who?

[TonyRPH]

My son is running a small business, and occasionally needs to perform credit checks on potential customers (the business is contract based, so customers will generally sign up for a fixed period).

I'm aware of companies like Call Credit etc., but does anyone know of any company who could provide a credit check on practically a one off basis?

He would only need to check potential customers perhaps every two to three months or so.

Thanks in advance.