Quote from Halal Burger:
Trying buying the bid or selling the ask on IB FX. You'll only get it if another customer crosses you or if the bid turns ask, or vice versa. It's not a true market or ECN. It's just a bucket shop with tighter spreads.
Interaktive brokers is a ECN.
Or they are lying:
From there homepage:
"Interactive Brokers Forex ECN offers traders direct access to interbank prices and dealing for orders as small as 25,000 USD
(or equivalent), and up to 10 million USD, or more. IBFX's ECN design provides best-execution functionality and a transparent
pricing structure. We offer trading in 13 currencies (USD, EUR, CHF, GBP, SEK, NOK, JPY, AUD, NZD, HKD, CAD, MXN, and special
conversion functionality in KRW) with market spreads as small as 1/2 PIP. The tight spreads and substantial liquidity are a result of combining quotation streams from 11 of the world's largest foreign exchange dealers which constitute more than two-thirds1 of the market share in the global interbank market.
Below are some reasons why professional individuals and institutions choose the IB Forex ECN.
Direct access to interbank forex quotes with no hidden price spreading, no markup, no kickbacks. Just the combination of real time prices from 12 of the world's largest FX dealing banks plus a transparent, low commission that avoids the conflict of interest of FX platforms which deal for their own account.