| Office Rent |
Fixed |
Use $4,500 per month in overhead for Month 1 through Month 60. |
Allocating rent to each client and understating base overhead. |
| Business Insurance |
Fixed |
Use $1,200 per month as recurring overhead, not a project charge. |
Tying insurance to client volume when the source treats it as monthly. |
| Software Subscriptions |
Fixed |
Use $2,800 per month unless a separate seat-based scale-up is modeled. |
Calling all software variable without a seat or usage driver. |
| Contract Subject Matter Experts |
Variable |
Model at 12.0% of first-year revenue, declining to 10.0% by the fifth year. |
Treating subcontractors like overhead and overstating contribution margin. |
| Research Database Subscriptions |
Variable |
Model at 3.5% of first-year revenue, declining to 2.5% by the fifth year. |
Forgetting the model ties this line to revenue, not a flat invoice. |
| Marketing & Client Acquisition |
Variable |
Model at 8.5% of first-year revenue and keep it separate from the $45,000 annual marketing budget. |
Double-counting acquisition spend by using both percentage and budget as the same driver. |
| Project-Specific Legal & Compliance |
Variable |
Model at 2.5% of first-year revenue, declining to 1.8% by the fifth year. |
Putting proposal-specific legal work into fixed professional services. |
| Travel & Entertainment |
Fixed |
Use $2,200 per month as fixed overhead in the source model. |
Mixing base travel with proposal-specific travel without a separate semi-variable line. |