In general, the QuickBooks software does not require a very high processor, so a minimum of Core i3 would do just fine for it. However, if you want to have an entirely uninterrupted service, we'd suggest you upgrade a bit and choose the 10th gen Core i5 or Core i7 if that is feasible under your budget. Again, it's not a prerequisite, but modern-day laptops usually come with at least Core i3 processors.