Depends on who the guarantors are. If they are entity affiliates and you used them in underwriting, then I would include them. For example, if your borrower is a newly formed LLC with no or little revenue in the previous year, and your guarantor is a parent company with millions in revenue, then you would include the guarantor.
From the data reporting guide:
Generally, an institution should rely on the revenues that it considered in making its credit decision when indicating whether a small business or small farm borrower had gross annual revenues of $1 million or less. For example, in the case of affiliated businesses, such as a parent corporation and its subsidiary, if the institution considered the revenues of the entity’s parent or a subsidiary corporation of the parent as well, then the institution would aggregate the revenues of both corporations to determine whether the revenues are $1 million or less. Alternatively, if the institution considered the revenues of only the entity to which the loan is actually extended, the institution should rely solely upon whether gross annual revenues are above or below $1 million for that entity.
However, if the institution considered and relied on revenues or income of a cosigner or guarantor that is not an affiliate of the borrower, such as a sole proprietor, it should not adjust the borrower’s revenues for reporting purposes.