How to Convert Currency on Interactive Brokers (Without Paying Too Much)

1. Log into Client Portal (web) or Trader Workstation
2. Navigate to 'Trade' → 'FX Trading' (or in TWS: open a Forex window from the menu)
3. Search for the currency pair: e.g., 'GBP' to find GBP.USD
4. Enter the amount you want to convert and the direction (buy USD with GBP, or sell USD for GBP)
5. Choose 'Market' for immediate execution or 'Limit' to set a target rate
6. Review the quote (you'll see the Ideal FX mid-market rate and the 0.1% markup)
7. Submit and confirm

1. Open the IBKR app and navigate to the 'Trade' tab.
2. Search for the currency pair — type 'GBP' or 'EUR' in the search bar, then select the .USD pair (e.g., GBP.USD).
3. Tap 'Trade' on the currency pair and enter the amount. Note whether you're entering the base currency (GBP) or quote currency (USD) amount.
4. Review the exchange rate shown — this is the mid-market rate plus 0.1%. Confirm.
5. The conversion settles T+1 (next business day for most pairs, though the funds are immediately available for trading).

If you buy a USD asset with a GBP account and have insufficient USD, IBKR will create a negative USD balance (a short position in USD). This is effectively borrowing — you'll pay overnight interest on the negative balance at IBKR's margin rate (approximately 4.5–6% USD rate). To settle, IBKR eventually auto-converts at a slightly less favourable 'auto-rate.' Always pre-convert manually in the Forex section to avoid this.

The FX market is open 24/5 (Sunday night to Friday night New York time). IBKR's 0.1% markup is fixed regardless of when you convert. However:

• Best liquidity (tightest bid-ask): London open (08:00–12:00 GMT) and New York open (13:00–17:00 GMT) overlap period provides maximum market liquidity.
• Avoid converting during illiquid periods: Friday afternoon New York (17:00–20:00 EST) and Sunday evening can have wider actual mid-market spreads that affect even IBKR's execution quality.
• For large amounts ($50,000+): consider splitting the conversion into 2–3 tranches over several days to minimize market impact.
• Limit orders: IBKR allows FX limit orders. If you're willing to wait for a specific rate, set a limit order rather than a market order. For patient investors, this can capture favorable rate moves.
• For most investors ($1,000–$50,000): timing matters less than method. The 0.1% IBKR rate vs 1% at HL is 10× more important than optimizing the FX timing.

IBKR supports 25+ currencies in a single account. You can hold GBP, USD, EUR, INR, AUD, SGD, and others simultaneously. This has practical advantages:

• You don't need to convert all your GBP to USD to buy US stocks — you can buy in stages, converting as needed.
• Interest on idle cash: IBKR pays interest on positive balances in most major currencies. USD balance earns approximately 4–5% (as of early 2026).
• Currency positions: sophisticated investors use IBKR's multi-currency structure to take explicit FX positions (going long EUR/GBP, for example) alongside their equity portfolio.
• Viewing the portfolio: in IBKR's performance reporting, you can view everything converted to your 'base currency' for a unified picture of your net worth.

IBKR's FX conversion requires a few deliberate steps. It's not automated — you must navigate to the Forex section and execute an explicit conversion. This is slightly inconvenient but ensures you see exactly what you're paying.

1. Log in to Client Portal (web) or IBKR Mobile. TWS also works but Client Portal is simpler for FX.
2. In Client Portal: go to Trade > Order Ticket. In the search box, type the currency pair you want (e.g., EUR.USD to buy USD with EUR, GBP.USD to buy USD with GBP).
3. Select the FX pair from search results. You'll see a live bid/ask spread.
4. Choose Buy or Sell: to convert GBP to USD, you are selling GBP (select Sell). To convert USD to GBP, you are buying GBP.
5. Enter the amount: specify in the base currency of the pair. For GBP.USD, the base is GBP — enter the GBP amount you want to convert.
6. Order type: use Market for amounts under £10,000. For larger amounts, use Limit at or slightly better than the current ask to potentially get a better fill.
7. Review the preview: it shows estimated USD received, the effective rate, and IBKR's commission (0.1%, min $2). Confirm and submit.
8. Settlement: FX conversions settle T+1 but your base currency balance updates immediately for trading purposes. You can buy stocks right away.

• Use limit orders for large amounts: for conversions above £10,000, place a limit order at the current midpoint (halfway between bid and ask). You may not fill immediately, but if the market moves to your price, you save 0.01–0.05% vs a market order.
• Avoid converting during market open/close: bid-ask spreads are widest in the first and last 30 minutes of major market sessions. Convert during quiet hours for tighter spreads.
• Batch your conversions: the $2 minimum means small conversions (under $2,000) have a higher effective rate. Convert at least $2,000 at a time to stay close to the 0.1% rate.
• Check the rate on both platforms: Client Portal and TWS may show slightly different spreads due to data feed latency. For large conversions, verify on TWS Mosaic > Forex screen.
• Overnight GBP.USD gap risk: if you place a limit order and leave it overnight, it may fill at an unexpected rate if there's a gap. For large conversions, use a Day order rather than GTC (Good Till Cancelled).

• IBKR FX best for: converting currency already inside IBKR before buying securities. Large amounts. Immediate reinvestment.
• Wise best for: sending money from one bank account to another in a different currency where neither account is IBKR. Wise charges 0.4–0.7% but provides actual bank accounts in multiple currencies.
• Bank wire (no conversion) best for: if you fund IBKR with GBP from UK bank and want to buy GBP-listed ETFs — no conversion needed at all. Buy VWRP (GBP-listed) instead of VWRA (USD-listed).
• Scenario comparison: UK investor funding IBKR with £5,000 GBP to buy VWRA (USD): Option A — Bank wire £5,000 GBP to IBKR → convert to USD (£5 cost at 0.1%) → buy VWRA. Option B — Buy VWRP (same fund, GBP-listed) directly with £5,000 → zero FX cost. Option B is always better when a GBP-listed share class exists.

• Q: What is IBKR's actual FX rate in practice? A: IBKR charges the interbank mid-rate plus 0.1% (minimum $2). In practice, the all-in cost including the tiny underlying bid-ask spread is 0.10–0.15% on major pairs like GBP/USD or EUR/USD during normal trading hours.
• Q: Can I convert currency on IBKR 24/7? A: No. FX markets trade 24/5 (Sunday 5pm ET to Friday 5pm ET), not weekends. IBKR's FX trading is available during forex market hours. Most major pair conversions can be done any weekday.
• Q: What is the minimum FX conversion amount at IBKR? A: No stated minimum, but the $2 minimum fee means the 0.1% effective rate only applies above $2,000. Below $2,000, your effective rate is: $2 / conversion amount. At $200, that's 1%.
• Q: How long does currency conversion settle at IBKR? A: FX conversions settle T+1 for most major pairs. However, your buying power updates immediately for same-day equity purchases — you don't need to wait for settlement to buy stocks.
• Q: Can I use a limit order for FX on IBKR? A: Yes. In Client Portal, when placing an FX order, select 'Limit' as the order type and enter your desired rate. For large conversions, a limit order slightly better than market can save 0.02–0.05% on large amounts. Day orders recommended — avoid leaving GTC FX limit orders overnight.