Change currency

{
  "billing_requests": {
    "currency": "EUR"
  }
}

{
  "billing_requests": {
    "id": "BRQ123",
    "created_at": "2015-01-01T12:00:00.000Z",
    "status": "pending",
    "account_information_request": {
      "country_code": "GB"
    },
    "mandate_request": {
      "description": "Top-up Payment",
      "currency": "GBP",
      "scheme": "bacs"
    },
    "payment_request": {
      "description": "Top-up Payment",
      "currency": "GBP",
      "scheme": "faster_payments",
      "amount": 1000,
      "app_fee": 100,
      "reference": "some-custom-ref"
    },
    "subscription_request": {
      "amount": 1000,
      "currency": "USD",
      "interval_unit": "monthly",
      "interval": 1,
      "app_fee": 100,
      "count": 5,
      "day_of_month": 28,
      "month": "january",
      "name": "12 month subscription",
      "payment_reference": "GOLDPLAN",
      "start_date": "2014-10-21"
    },
    "instalment_schedule_request": {
      "name": "Invoice 4404",
      "currency": "USD",
      "total_amount": 1000,
      "payment_reference": "GOLDPLAN",
      "app_fee": 100,
      "instalments_with_dates": [
        {
          "amount": 250,
          "charge_date": "2020-11-03"
        }
      ],
      "instalments_with_schedule": {
        "start_date": "2014-10-21",
        "interval": 1,
        "interval_unit": "monthly",
        "amounts": [
          1000
        ]
      }
    },
    "actions": [
      {
        "type": "collect_bank_account",
        "status": "pending",
        "required": true,
        "completes_actions": [
          "collect_bank_account"
        ],
        "requires_actions": [
          "collect_bank_account"
        ],
        "available_currencies": [
          "GBP"
        ],
        "available_country_codes": [
          "GB"
        ],
        "institution_guess_status": "pending"
      }
    ],
    "resources": {
      "customer": {
        "id": "CU123",
        "created_at": "2014-01-01T12:00:00.000Z",
        "email": "user@example.com",
        "given_name": "Frank",
        "family_name": "Osborne",
        "company_name": "Hamilton Trading Ltd.",
        "language": "en",
        "phone_number": "+64 4 817 9999"
      },
      "customer_billing_detail": {
        "id": "CU123",
        "created_at": "2014-01-01T12:00:00.000Z",
        "address_line1": "221B Baker Street",
        "address_line2": "Marylebone",
        "address_line3": "City of Westminster",
        "city": "London",
        "region": "Greater London",
        "postal_code": "NW1 6XE",
        "country_code": "GB",
        "swedish_identity_number": "556564-5404",
        "danish_identity_number": "2205506218",
        "ip_address": "127.0.0.1"
      },
      "customer_bank_account": {
        "id": "BA123",
        "created_at": "2014-01-01T12:00:00.000Z",
        "account_holder_name": "Billie Jean",
        "account_number_ending": "1234",
        "account_type": "savings",
        "country_code": "GB",
        "currency": "EUR",
        "bank_name": "BARCLAYS BANK PLC",
        "enabled": true,
        "bank_account_token": "bat_f975ab3c-ecee-47a1-9590-5bb1d56fa113",
        "payer_name_verification_result": "full"
      }
    },
    "links": {
      "customer": "CU123",
      "creditor": "CR123",
      "organisation": "OR123",
      "customer_bank_account": "BA123",
      "account_information_request": "AIR123",
      "payment_request": "PRQ123",
      "payment_request_payment": "PM123",
      "mandate_request": "MRQ123",
      "mandate_request_mandate": "MD123",
      "subscription_request": "SBR123",
      "subscription_request_subscription": "SB123",
      "instalment_schedule_request": "ISR123",
      "instalment_schedule_request_instalment_schedule": "IS123",
      "payment_provider": "PP123"
    }
  }
}