Horizontal integration refers to the merger or acquisition of two or more companies that operate in the same industry or market. For individuals, the tax implications of horizontal integration may depend on whether they own shares in the companies involved in the merger or acquisition. For example, if an individual owns shares in a company that is being acquired, they may be subject to capital gains tax on any profit they make from the sale of their shares. For companies, the tax implications of horizontal integration may include assessing the tax treatment of assets and liabilities, such as goodwill or intangible assets, and determining the tax treatment of any losses or gains resulting from the merger or acquisition. Additionally, companies may need to consider the tax implications of any debt financing they undertake as part of the integration process.