diff --git a/src/company_gui.h b/src/company_gui.h
index f6149b05fb..10b1c3974e 100644
--- a/src/company_gui.h
+++ b/src/company_gui.h
@@ -1,11 +1,30 @@
 /*
  * This file is part of OpenTTD.
- * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
- * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * OpenTTD is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation, version 2.
+ *
+ * OpenTTD is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
  */
 
-/** @file company_gui.h GUI Functions related to companies. */
+/**
+ * @file company_gui.h
+ * @brief GUI Functions and utilities related to managing and displaying
+ *        companies and their associated assets in OpenTTD.
+ *
+ * This header provides a set of functions for drawing company icons,
+ * displaying company-specific windows (finances, station lists, etc.),
+ * and invalidating or closing GUI elements when needed. It draws upon
+ * fundamental data structures like #CompanyID, #GroupID, and game-level
+ * constructs for rendering.
+ */
 
 #ifndef COMPANY_GUI_H
 #define COMPANY_GUI_H
@@ -14,16 +33,81 @@
 #include "group.h"
 #include "gfx_type.h"
 
+/**
+ * Retrieve a text color suitable for rendering strings associated with
+ * a given company. This color is typically used to distinguish ownership
+ * or branding visually in GUIs or tooltips.
+ *
+ * @param company The ID of the company to derive text color from.
+ * @return An appropriate #TextColour for the specified company.
+ */
 TextColour GetDrawStringCompanyColour(CompanyID company);
+
+/**
+ * Render a company’s icon at a specified coordinate on the screen.
+ *
+ * @param c The ID of the company whose icon will be drawn.
+ * @param x The X-coordinate where the icon should be placed.
+ * @param y The Y-coordinate where the icon should be placed.
+ */
 void DrawCompanyIcon(CompanyID c, int x, int y);
 
+/**
+ * Show the window that allows customization or viewing
+ * of a company's livery. This may relate to vehicle or station
+ * color schemes, logos, etc.
+ *
+ * @param company The ID of the company in question.
+ * @param group   The group for which this livery applies (e.g., default group).
+ */
 void ShowCompanyLiveryWindow(CompanyID company, GroupID group);
+
+/**
+ * Display a station list window for the specified company.
+ *
+ * @param company The ID of the company whose station list should be displayed.
+ */
 void ShowCompanyStations(CompanyID company);
+
+/**
+ * Bring up the company finances window for inspection of
+ * income, expenses, loans, and other monetary details.
+ *
+ * @param company The ID of the company whose finances are shown.
+ */
 void ShowCompanyFinances(CompanyID company);
+
+/**
+ * Open a general information window for the company, potentially
+ * including name, management, performance rating, etc.
+ *
+ * @param company The ID of the company for which to open the info window.
+ */
 void ShowCompany(CompanyID company);
 
+/**
+ * Invalidate the windows belonging to a given company to
+ * trigger a re-draw or refresh event. This is especially useful when
+ * crucial data (ownership, color scheme, etc.) has changed.
+ *
+ * @param c Pointer to the Company object to invalidate windows for.
+ */
 void InvalidateCompanyWindows(const Company *c);
+
+/**
+ * Close all GUI windows associated with a specified company.
+ *
+ * @param company The ID of the company whose windows should be closed.
+ */
 void CloseCompanyWindows(CompanyID company);
+
+/**
+ * Mark infrastructure-related windows of a company as 'dirty'
+ * so they get refreshed or redrawn. This is useful if tracks,
+ * stations, or depots have changed in a way that affects the display.
+ *
+ * @param company The ID of the company to be updated.
+ */
 void DirtyCompanyInfrastructureWindows(CompanyID company);
 
 #endif /* COMPANY_GUI_H */