Dues and subscriptions groups the recurring charges that are neither materials nor wages: trade association memberships, software, publications, and professional bodies.
Why it is worth its own line
Each charge is small enough to approve without thought and recurring enough to become permanent. Grouped together the total is frequently several times what the owner would estimate.
Scattered through general expenses, no single line is large enough to prompt anyone to look — see overhead reduction.
The two kinds
Dues — trade associations, professional bodies, chambers, licensing bodies. Some are a condition of holding a licence and are not optional; others are bought for referrals and credibility and should be judged on whether they deliver either.
Subscriptions — chiefly software, which has its own article because of how it accumulates and how it is priced per user — see software subscriptions.
Reviewing it
Annually, against the list rather than from memory. The questions are the same for every line: is it still used, is it still needed, and is the tier still right.
The common findings are a subscription for a tool replaced a year ago, seats for people who have left, and an annual membership renewed automatically since before anyone remembers.
Why it drifts upward
Nothing in a subscription prompts cancellation. It renews unless someone acts, which means the default state of this category is growth — see operational waste and expense trend.