Every retailer starts with one P&L, because at a handful of locations, one P&L is genuinely enough. The question isn't whether store-level reporting would help — it's at what point the consolidated view stops being sufficient to run the business.

What changes as locations multiply

With more locations comes more variance: different rent structures, different labor markets, different local demand patterns. A consolidated P&L doesn't just get bigger as you add stores — it gets less useful, because it averages together businesses that are increasingly different from each other.

What a store-level P&L needs to separate

Where the line actually sits

There's no universal store count where this becomes mandatory, but the signal is consistent: once you can no longer explain a swing in the consolidated number by pointing to a specific location, cause, and timeframe, store-level P&Ls have already become necessary — you just haven't built them yet.