DCC Calculations

This DCC Calculations section describes the process that should be used when calculating the dynamic currency conversion.

On this page:

Exchange Rate Calculation

The Base Exchange Rates held on the Authorisation Host are truncated at the 6th minor decimal place.

  • The mark up agreed with the merchant is added into the base rate and then the marked-up rate is once again truncated at the 6th minor decimal place.
  • If there is a minor 7th decimal place it is truncated. No rounding takes place.

Example

  • Base Rate GBP to EUR = 0.725800
  • Merchant Mark-up = 3.25%
Item Figure

Final Rate

= 0.725800 + (0.725800 x 3.250000 / 100)
= 0.725800 + 0.0235885= 0.7493885

(Rate is truncated)

= 0.749388

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Transaction Amount Calculation

The process used for calculating the DCC transaction amount is as follows:

  • The final amount in the merchant’s pricing currency is converted using the marked-up exchange rate.
  • The amount is then rounded to two decimal places.
  • The amount is rounded up when the third minor unit is a value of 5 or more and is rounded down if the third minor unit is a value of 4 or less.
Note: The only exception is when solutions using the Elavon POS V2, Elavon POS V3, and Polish ISO 8583 protocols round the amount to zero decimal places for currencies (e.g. JPY) with a zero minor decimal place exponent. See the appropriate authorisation specifications for details.
Important: The amount sent in the authorisation must match the amount provided in the settlement records. If there is a discrepancy in the authorisation and clearing amounts the merchant would be subject to integrity fees.

Examples

Example 1: Rounding up.
Item Figure
Merchant Pricing Currency €150.000
FX Rate 0.749388
Transaction Amount (Pre Rounding) £112.408
Transaction Amount (Post Rounding) £112.410

 

Example 2: Rounding up.
Item Figure
Merchant Pricing Currency €400.000
FX Rate 0.749388
Transaction Amount (Pre Rounding) £299.755
Transaction Amount (Post Rounding) £299.760

 

Example 3: Rounding down.
Item Figure
Merchant Pricing Currency €140.000
FX Rate 0.749388
Transaction Amount (Pre Rounding) £104.914
Transaction Amount (Post Rounding) £104.910

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❮ DCC-Specific Transaction Requirements Next: DCC-Consumer/Cardholder Choice ❯