It is now easier than ever to set up your business support and tax investigation service by monthly direct debit. Your letter/email will tell you the monthly amount but if you are unsure, please click here for a reminder. In summary, as well as employment law, commercial legal, health and safety support, we will deal with any HMRC enquiry of any kind (e.g. tax, VAT, PAYE etc.) at no cost to yourself. Read more. If you are already paying McPhersons by Go Cardless, you can add the Tax Investigation Service to your monthly direct debit here.