Your bank is charging you a fee you have never seen on a fee schedule. It does not show up as a line item. It is buried in the exchange rate itself — and for most US businesses paying international contractors, it costs more than all their visible fees combined.
How the exchange rate margin works
Every currency pair has a "mid-market rate" — the actual exchange rate between two currencies, the midpoint between what buyers and sellers in the global currency market are willing to pay. This is the rate you see on Google, XE.com, or Bloomberg. It is the real rate.
- •When your bank converts USD to MXN for a contractor payment, they use a rate worse than the mid-market rate
- •The difference between the mid-market rate and what your bank charges you is the exchange rate margin
- •Typical US bank margin: 2-4% on international conversions
- •On a $3,000 payment at a 3% margin: your contractor receives the equivalent of $2,910, not $3,000
- •The $90 difference does not show up as a fee — it just disappears into the bank's spread
- •This happens on every single international payment, every month
How to calculate what you are actually paying
- •1. Find the mid-market rate: Google "USD to MXN" or visit xe.com — note the rate
- •2. Check what rate your bank used: look at the transaction receipt or your online banking detail
- •3. Calculate the difference: (mid-market rate - bank rate) / mid-market rate = your margin percentage
- •4. Multiply by your payment amount to find the hidden cost per transfer
- •Example: mid-market 17.50 MXN/USD, bank used 16.98 MXN/USD. Margin: (17.50-16.98)/17.50 = 2.97%. On $3,000: hidden cost = $89
The annual cost for a typical small business
Ejemplo
Small agency with 3 Latin American contractors, each paid $3,000/month. Bank wire fees: $35/wire x 3 x 12 = $1,260/year. Exchange rate margin at 3%: $90 x 3 x 12 = $3,240/year. Total annual overhead: $4,500. Same payments through Wise Business: $18 average fee x 36 payments = $648/year. Annual savings: $3,852.
Why banks do this
- •Currency conversion is one of the most profitable products in retail and business banking
- •The margin is legal and disclosed (in fine print) but not prominently shown
- •Most business owners focus on the wire fee and ignore the conversion cost
- •Banks have little incentive to change this because most customers never calculate the real cost
- •The rise of fintech platforms like Wise has forced some banks to be more competitive, but margins remain high
The fix
- •Use a platform that charges the mid-market rate: Wise Business, Revolut Business, or similar
- •Wise Business fee: 0.4-0.9% flat, shown transparently before you confirm
- •This is the real fee — there is no exchange rate margin on top
- •The total cost of a Wise Business transfer is typically 5-8x lower than a bank wire for the same amount
- •Setup takes 15 minutes and your first transfer is free
Disclosure: CréditoClaro may receive a commission when you open a Wise Business account. Our analysis of exchange rate margins reflects real market data as of 2026.