Compare the monthly fulfilment cost of Amazon FBA against Seller Fulfilled Prime (SFP) via a UK 3PL like PackPro. Both models give your listings the Prime badge — the difference is entirely in fulfilment cost, operational control, and storage flexibility.
With FBA, Amazon charges a per-unit fulfilment fee based on size and weight (from ~£2.50 for a large letter to £6.50+ for a 5kg parcel), plus monthly storage — which triples in October–December and incurs aged inventory surcharges after 181 days. With SFP via PackPro, you pay pick and pack plus courier postage instead, at a flat daily storage rate with no seasonal surcharge or aged inventory penalties.
The referral fee is identical for FBA and SFP — this comparison focuses purely on the fulfilment and storage cost difference. For products in the 2kg+ weight band, SFP with a 3PL is frequently cheaper per order than FBA while maintaining the Prime badge. See our full Amazon FBA vs 3PL guide or Seller Fulfilled Prime guide for more context. Contact PackPro for an exact SFP quote.