What piece of information is NOT part of signing up for the Making Tax Digital service?

When signing up for the Making Tax Digital (MTD) service, specific information is required to ensure that businesses can comply with digital tax reporting obligations. The correct answer indicates that 'Business bank account details' are not part of the necessary information for the MTD registration process.

The Government Gateway user ID and password are essential for accessing government services online; they secure and authenticate the individual's identity in the system. Additionally, providing a Company Registration Number and Unique Taxpayer Reference is crucial, as these identifiers help HMRC link the tax records to the correct business entity. If the business is a sole trader, the National Insurance number is also needed, as it further verifies the taxpayer's identity and connects to their tax records.

In contrast, business bank account details are not a part of this specific registration process. While such details might be relevant for various business operations or transactions, they are not required for the initial sign-up to the MTD service, hence why this choice is the correct answer.