The broker with the lowest spread on the euro and US dollar pair may not offer the lowest costs on the sterling pairs you trade.
EUR/USD is the reference point in most forex broker comparison tables. That is understandable: it is one of the market's most actively traded pairs and often carries a broker's tightest quoted spread. Yet a single EUR/USD figure cannot show what a UK trader will pay on GBP/USD, EUR/GBP or another pair that forms a larger share of their activity.
A useful comparison starts with the instruments a trader actually uses. It then matches the account type, trading hours and full cost structure. EUR/USD remains relevant, but it should be treated as a starting point rather than a complete ranking of broker costs.
Why EUR USD Dominates Comparison Tables
The global foreign exchange market is concentrated in a relatively small group of major currencies. The Bank for International Settlements reported that the US dollar was on one side of 89.2 per cent of all trades in April 2025, while sterling accounted for 10.2 per cent. High liquidity in major dollar pairs can support tighter pricing, which helps explain why EUR/USD is commonly used as a headline benchmark.
That benchmark is still incomplete. Spreads vary by currency pair, broker, account and market conditions. A firm that prices EUR/USD competitively may rank differently on GBP/USD or EUR/GBP. Traders who choose a broker from one headline number can therefore reach the wrong conclusion about their own likely costs.
Practical check List the three currency pairs you traded most often during the last quarter. Use those pairs, rather than a generic market benchmark, as the basis for your first comparison.
What the Spread Represents
The spread is the difference between the bid price, at which a position can be sold, and the ask price, at which it can be bought. When a position opens, it begins on the other side of that gap. The spread is therefore embedded in the execution price. A trader does not automatically pay the same quoted spread twice, although the spread prevailing when the position is closed also affects the final result.
The cash value depends on the spread, position size and currency of the account. Frequency matters as well: a small difference per transaction may become material across many trades. For accounts that charge commission, the comparison should add the stated commission, including whether it is quoted per side or for a complete round trip.
Spread and commission are only part of the calculation. Slippage, overnight financing, currency conversion charges, inactivity fees and withdrawal costs may also affect the total. The cheapest broker on one measure may not be the cheapest for a trader's strategy as a whole.
Why Timing and Account Type Matter
Spreads are variable on many retail trading accounts. They can tighten during liquid market hours and widen when liquidity falls, volatility rises or important economic data is released. Two readings are comparable only when the underlying conditions are reasonably aligned. A figure recorded during the London and New York overlap should not be compared uncritically with a figure taken late in the evening or during a volatile announcement.
Account structure also changes the result. A standard account may include most of the broker's charge in the spread, while a commission-based account may advertise a lower spread and add a separate fee. Comparison tables should identify the account type and report an all-in cost where the necessary data are available.
Advertised 'from' spreads can show the lowest available quote, but they do not establish what a trader will usually receive. Live-account observations can add context, provided the publisher explains when and how the data were gathered. They still represent a sample rather than a guarantee of future pricing or execution.
How to Interpret Typical Spread Measures
Comparison publishers may report the minimum, mean, median or mode. Each measure answers a different question. The minimum identifies the lowest observed value. The mean reflects all observations but can move when a small number of unusually wide readings occur. The median identifies the midpoint of the sample. The mode reports the value observed most often.
A modal spread can be useful when quotes repeat at standard increments, but it is not automatically the spread a trader will see most of the time. The result can depend on rounding, sample size and the times selected for measurement. A responsible comparison therefore publishes the method alongside the figure and avoids presenting any one statistic as a universal trading cost.
A Sterling Aware Comparison
For readers whose activity includes sterling, a comparison should place GBP/USD and EUR/GBP alongside EUR/USD. It should use the same observation windows for each broker, identify the relevant account configuration and state whether the figures came from live, demo or broker-supplied data.
CompareForexBrokers.co.uk, a commercial broker comparison publisher, says its methodology records live-account spreads at 09:00, 12:00 and 16:00 London time over three trading days and reports a modal value for each tested account configuration. These observation points cover several parts of the UK trading day and allow sterling pairs to be assessed on the same basis as EUR/USD.
That approach provides a structured snapshot, but its limits should remain visible. Three days cannot capture every liquidity condition, market event or seasonal pattern. The results may also change as brokers adjust pricing. Readers should check the test date, sample size, account type and any published raw data before applying a ranking to their own trading pattern.
Commercial relationships also matter. The publisher discloses that it may receive referral fees when readers open accounts with partner brokers. That does not by itself invalidate the data, but the relationship should be considered alongside the methodology, inclusion criteria and presentation of results.
What a Balanced Comparison Should Show
Spreads for the currency pairs the reader expects to trade, including GBP/USD and EUR/GBP where relevant
The precise account type and any commission charged per side or per round trip
The dates, clock times, sample size and market conditions used for testing
A clear definition of the statistic reported, such as minimum, mean, median or mode
Potential costs beyond the spread, including financing, conversion and inactivity charges
Execution factors such as slippage, order handling and platform reliability
The broker's exact legal entity, Financial Conduct Authority reference number and relevant permissions
Practical check Recalculate the ranking using your main pairs, usual trading hours and expected position size. If a table does not disclose its source data or method, treat its result as promotional information rather than a complete cost comparison.
Regulation Comes Before Price
A low spread does not replace regulatory due diligence. UK readers should verify the broker's exact legal entity on the Financial Conduct Authority's Financial Services Register and confirm that its permissions cover the service being offered. Similar trading names can be used by different entities within the same group, and protections may depend on which entity holds the account.
Forex and contracts for difference are leveraged products. Leverage can magnify gains and losses, and a narrow spread does not reduce market risk. Traders should read the broker's risk warning, client agreement and key product information before depositing funds. Regulatory status, complaint routes and client-money arrangements deserve more weight than a marginal difference in quoted spread.
The Better Way to Use a Comparison Table
EUR/USD remains a useful reference because it offers a consistent starting point across many brokers. The mistake is allowing that one figure to stand in for every pair, account and trading session. A trader who mainly uses GBP/USD or EUR/GBP should compare those prices directly, under conditions that resemble their own activity, and then add commission and other relevant charges.
The most useful comparison is specific to the decision being made. It shows the pairs that matter, explains how the figures were produced and makes the commercial context clear. That gives readers a better basis for assessing cost while keeping regulation, execution quality and risk in view.
Sources
Bank for International Settlements 2025 Triennial Central Bank Survey
Financial Conduct Authority guidance on financial promotions
Risk Disclosure
Forex and CFD trading involves leverage and carries a high risk of rapid losses. This article provides general information only and does not constitute financial, investment or legal advice. Readers should verify a broker's legal entity and permissions on the FCA Financial Services Register and review the broker's risk disclosures before trading.