Start by identifying which costs are truly shared. Rent, utilities, insurance, IT systems, and office supplies often benefit both programs and administration. Salaries for staff who split time between program delivery and admin work are another big one. Costs that are 100% program or 100% administrative should be coded directly and don’t need allocation at all. The allocation question only applies to expenses that genuinely serve both functions.

The three most common allocation methods are time spent, square footage, and direct benefit. Time-based allocation works well for salaries and shared labor. If your executive director spends 60% of their time on program oversight and 40% on fundraising and management, the salary splits accordingly. Square footage works for facility costs. If your building is 5,000 square feet and 3,500 of that is used for program activities, 70% of rent and utilities go to program expenses. Direct benefit applies when you can trace an expense to its actual use, like a shared copier where you can track print volume by department.

Pick the method that most accurately reflects how resources are actually used. You can use different methods for different cost categories. Time-based for salaries, square footage for occupancy, and usage-based for equipment is a perfectly reasonable approach. What matters is that each method makes logical sense for the type of expense it’s applied to.

The program expense ratio is what donors, grantors, and watchdog organizations look at first. They want to see at least 75% of total expenses going to program services. Falling below that raises questions about whether the organization is efficiently pursuing its mission. This doesn’t mean you should manipulate allocations to hit a number. It means your allocation methodology should be accurate, and if admin costs are genuinely high, that’s a management issue to address rather than an accounting issue to obscure.

Documentation is where most nonprofits fall short. Write down your allocation methodology in a formal policy document. Include the rationale for why each method was chosen. Keep supporting data like time studies, floor plans, or usage logs that back up your percentages. If you’re ever audited or a major donor asks how you calculated your program expense ratio, you need to be able to show your work clearly.

Apply your methodology consistently from year to year. Changing allocation methods annually looks like you’re shopping for favorable numbers. If circumstances genuinely change, like moving to a new building where program space is a different percentage, update the allocation and document why it changed. The IRS expects consistency, and your Form 990 is a public document that anyone can review.

One common mistake is allocating fundraising costs as program expenses. Fundraising is its own category on Form 990 and needs to be reported separately. An event that has both a fundraising component and a program education component requires a joint cost allocation under ASC 958-720, which has specific criteria that must be met before you can split those costs.

Getting this right matters beyond compliance. Accurate cost allocation gives your board real data about what programs actually cost to run, which drives better decisions about where to invest resources. If you need help structuring your chart of accounts and allocation methodology, working with professional bookkeeping services that understand nonprofit reporting will save you significant headaches when Form 990 season arrives.