Bunker Adjustment Factor (BAF)

The Bunker Adjustment Factor (BAF) — also called Bunker Surcharge or Fuel Surcharge — is a variable fee charged by ocean carriers to account for fluctuations in the price of bunker fuel (the heavy marine fuel used to power container ships). It is one of the major variable components of ocean freight pricing and can represent a significant portion of total shipping costs, particularly on long-haul routes.

What is Bunker Fuel?

Bunker fuel is the collective term for the fuel used in shipping. Traditionally, most ships used Heavy Fuel Oil (HFO), an extremely dense, viscous residual oil that is cheap but highly polluting. Since January 2020, the IMO 2020 regulation mandates that ships burn fuel with sulfur content below 0.5% globally (down from 3.5%), and below 0.1% in Emission Control Areas (ECAs) like the North Sea, Baltic Sea, and US coastal zones.

Ships now use either:

• Very Low Sulfur Fuel Oil (VLSFO): Compliant with IMO 2020, more expensive than HFO
• Marine Gas Oil (MGO): Distillate fuel, very clean but most expensive
• Liquefied Natural Gas (LNG): Some newer vessels are LNG-powered, offering both fuel savings and dramatically lower emissions
• Scrubbers: Some operators fit HFO-burning vessels with exhaust scrubbers that remove sulfur, allowing continued HFO use at lower compliance cost

How BAF is Calculated

Carriers calculate BAF based on their actual bunker consumption for a given trade lane, multiplied by the market price of compliant fuel at the ports they call on. BAF rates are published by the carrier and typically updated monthly or quarterly.

Carriers index BAF to market fuel price benchmarks published by agencies like Platts, S&P Global, or regional exchanges. When fuel prices spike — as they did in 2022 when Brent crude exceeded $130/barrel — BAF charges increase substantially, sometimes representing $500–$1,500 per TEU on Asia-Europe routes.

BAF vs. EBS vs. LSS

Ocean freight invoices can include several related fuel charges with different names across different carriers:

• BAF (Bunker Adjustment Factor): The classic fuel surcharge
• EBS (Emergency Bunker Surcharge): A temporary additional surcharge applied during sudden fuel price spikes
• LSS (Low Sulphur Surcharge): Introduced by many carriers in 2019–2020 to recover the incremental cost of IMO 2020 compliant fuels
• CAF (Currency Adjustment Factor): Related to currency, not fuel — but sometimes confused with BAF

Negotiating BAF

Unlike base ocean freight rates (which are negotiable), BAF is often presented by carriers as a standard, non-negotiable charge. Large shippers on long-term contracts can sometimes negotiate:

• BAF caps (maximum exposure regardless of price increases)
• BAF-inclusive freight rates for periods of price stability
• More transparent BAF calculation methodology disclosure

For most shippers, BAF is a pass-through cost that must be factored into landed cost calculations alongside base freight, THC, documentation fees, and customs costs.