Massively complex but working never the less.

app/Helpers/Csv/Converter/OpposingAccountIban.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace FireflyIII\Helpers\Csv\Converter;
+
+use Auth;
+use FireflyIII\Models\Account;
+
+/**
+ * Class OpposingAccountIban
+ *
+ * @package FireflyIII\Helpers\Csv\Converter
+ */
+class OpposingAccountIban extends BasicConverter implements ConverterInterface
+{
+
+    /**
+     * If mapped, return account. Otherwise, only return the name itself.
+     *
+     * @return Account|string
+     */
+    public function convert()
+    {
+        if (isset($this->mapped[$this->index][$this->value])) {
+            $account = Auth::user()->accounts()->find($this->mapped[$this->index][$this->value]);
+
+            return $account;
+        } else {
+            $set = Auth::user()->accounts()->get();
+            /** @var Account $account */
+            foreach ($set as $account) {
+                if ($account->iban == $this->value) {
+                    return $account;
+                }
+            }
+
+            return $this->value;
+        }
+    }
+}

app/Helpers/Csv/Converter/OpposingAccountId.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace FireflyIII\Helpers\Csv\Converter;
+
+use Auth;
+use FireflyIII\Models\Account;
+
+/**
+ * Class OpposingName
+ *
+ * @package FireflyIII\Helpers\Csv\Converter
+ */
+class OpposingAccountId extends BasicConverter implements ConverterInterface
+{
+
+
+    /**
+     * @return Account
+     */
+    public function convert()
+    {
+        if (isset($this->mapped[$this->index][$this->value])) {
+            $account = Auth::user()->accounts()->find($this->mapped[$this->index][$this->value]);
+
+        } else {
+            $account = Auth::user()->accounts()->find($this->value);
+        }
+
+        return $account;
+
+    }
+}

app/Helpers/Csv/Converter/OpposingAccountName.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace FireflyIII\Helpers\Csv\Converter;
+
+use Auth;
+use FireflyIII\Models\Account;
+
+/**
+ * Class OpposingName
+ *
+ * @package FireflyIII\Helpers\Csv\Converter
+ */
+class OpposingAccountName extends BasicConverter implements ConverterInterface
+{
+
+    /**
+     * If mapped, return account. Otherwise, only return the name itself.
+     *
+     * @return Account|string
+     */
+    public function convert()
+    {
+        if (isset($this->mapped[$this->index][$this->value])) {
+            $account = Auth::user()->accounts()->find($this->mapped[$this->index][$this->value]);
+
+            return $account;
+        } else {
+            return $this->value;
+        }
+    }
+}

app/Helpers/Csv/Converter/OpposingName.php

@@ -1,24 +0,0 @@
-<?php
-
-namespace FireflyIII\Helpers\Csv\Converter;
-
-/**
- * Class OpposingName
- *
- * @package FireflyIII\Helpers\Csv\Converter
- */
-class OpposingName extends BasicConverter implements ConverterInterface
-{
-
-    /**
-     * This method cannot search yet for the correct account (Expense account, Revenue account or Asset account) because simply put,
-     * Firefly doesn't know yet if this account needs to be an Expense account or a Revenue account. This depends
-     * on the amount which is in the current row and that's a big unknown.
-     *
-     * @return mixed
-     */
-    public function convert()
-    {
-        return $this->value;
-    }
-}