PP-8405 - Adds information about users outside of the UK (#1016)

Author: NathanD-GDS

source/making_payments/index.html.md.erb

@@ -235,4 +235,17 @@ that’s not `null`, you can cancel the payment. For example:
   "href": "https://publicapi.payments.service.gov.uk/v1/payments/hu20sqlact5260q2nanm0q8u93/cancel",
   "method": "POST"
 }
-```
+```
+
+## Other considerations when taking a payment
+
+### Taking payments from users outside of the UK
+
+GOV.UK Pay only supports payments in British pounds (GBP), however users from outside of the UK can still make payments.
+
+In this situation:
+
+* the user’s bank will do a currency conversion into GBP if the payment card uses a foreign currency
+* the user’s bank may charge a conversion fee and give the user an unfavourable exchange rate
+* payments are more likely to be declined during fraud checks
+* your PSP may charge you additional transaction fees for cards issued outside the UK

source/payment_flow/index.html.md.erb

@@ -58,7 +58,9 @@ When your service redirects your user to `next_url`, they’ll see an **Enter pa
 * billing address
 * email address
 
-If your service takes [digital wallet payments](/digital_wallets/), your user can also choose to pay with Apple Pay or Google Pay from this page.
+If your service takes [digital wallet payments](/digital_wallets/), your user can also choose to pay with Apple Pay or Google Pay from this page. 
+
+We also support [users paying from outside of the UK](/making_payments/#taking-payments-from-users-outside-of-the-uk).
 
 This page also shows the `description` and the amount your user has to pay, making it clear what they’re paying for.