Most successful FBA brands at scale — 2,000 to 50,000 units per month — operate without any owned warehouse space. They use a combination of supplier direct-to-3PL shipping, 3PL prep, and Amazon FBA storage.
The key to scaling without a warehouse is giving your 3PL enough lead time and volume visibility that they can staff and stage correctly. Brands that treat their 3PL as a partner rather than a vendor get faster turnarounds.
At higher volume, negotiate a dedicated workflow at your 3PL — meaning your inventory does not share a prep line with small-volume clients. This protects your timeline during peak periods.
Review your unit economics quarterly. As volume increases, per-unit prep cost should decrease. If it does not, either your SKU complexity is growing faster than your efficiency gains, or it is time to renegotiate rates.