Concerns about conflicts of interest are becoming more prevalent. Ideally, trustees should avoid conflicts by keeping family, business and charity interests entirely separate. However, the best trustees are sometimes people with expertise from related businesses or charities.
The Charity Commission's definition is clear: "a conflict of interest is any situation in which a trustee's personal interests, or interests they owe to another body, may (or may appear to) influence or affect the trustee's decision making". This applies to financial and other benefits, to both you and your close family.
The key is to consider whether there could be perception of a conflict. If so, transparency and careful management are essential. Avoid any involvement in decisions about the issue, inform the chair that you might be conflicted, step outside meetings when the item is discussed and ensure your absence is noted in the minutes.
If potential conflicts arise more than a few times, consider relinquishing your trusteeship and contributing in other ways. This will ensure that the reputation of your charity, and that of the wider sector, are not put at risk.