diff --git wordcamp.org/public_html/wp-content/plugins/wc-post-types/css/admin.css wordcamp.org/public_html/wp-content/plugins/wc-post-types/css/admin.css
index b5657e8..4909af1 100644
--- wordcamp.org/public_html/wp-content/plugins/wc-post-types/css/admin.css
+++ wordcamp.org/public_html/wp-content/plugins/wc-post-types/css/admin.css
@@ -40,3 +40,9 @@
 			display: table-caption;
 			font-weight: bold;
 		}
+.wcbsponsor-note {
+	margin-bottom: 1em;
+}
+.wcbsponsor-note-meta {
+	font-weight: 800;
+}
\ No newline at end of file
diff --git wordcamp.org/public_html/wp-content/plugins/wc-post-types/views/sponsors/metabox-notes.php wordcamp.org/public_html/wp-content/plugins/wc-post-types/views/sponsors/metabox-notes.php
new file mode 100644
index 0000000..818fef0
--- /dev/null
+++ wordcamp.org/public_html/wp-content/plugins/wc-post-types/views/sponsors/metabox-notes.php
@@ -0,0 +1,38 @@
+<?php if ( empty ( $existing_notes ) ) : ?>
+
+	<?php _e( 'There are no notes yet.', 'wordcamporg' ); ?>
+
+<?php else : ?>
+
+	<?php foreach ( $existing_notes as $note ) : ?>
+		<div class="wcbsponsor-note">
+			<span class="wcbsponsor-note-meta">
+				<?php echo esc_html( date( 'Y-m-d', $note['timestamp'] ) ); ?>
+				<?php echo esc_html( get_the_author_meta( 'nickname', $note['author_id'] ) ); ?>:
+			</span>
+
+			<?php echo esc_html( $note['message'] ); ?>
+		</div>
+	<?php endforeach; ?>
+
+<?php endif; ?>
+
+<div>
+	<h3>
+		<label for="wcbsponsor_new_note">
+			<?php _e( 'Add a Note', 'wordcamporg' ); ?>
+		</label>
+
+		<?php if ( current_user_can( 'manage_network' ) ) : ?>
+			<p class="description">(visible to organizers)</p>
+		<?php endif; ?>
+	</h3>
+
+	<textarea id="wcbsponsor_new_note" name="wcbsponsor_new_note" class="large-text"></textarea>
+
+	<?php submit_button(
+		esc_html__( 'Add Note', 'wordcamporg' ),
+		'secondary',
+		'wcbsponsor_add_note'
+	); ?>
+</div>
diff --git wordcamp.org/public_html/wp-content/plugins/wc-post-types/wc-post-types.php wordcamp.org/public_html/wp-content/plugins/wc-post-types/wc-post-types.php
index 4fd6e51..91671c9 100644
--- wordcamp.org/public_html/wp-content/plugins/wc-post-types/wc-post-types.php
+++ wordcamp.org/public_html/wp-content/plugins/wc-post-types/wc-post-types.php
@@ -1514,6 +1514,7 @@ class WordCamp_Post_Types_Plugin {
 		add_meta_box( 'sponsor-info',      __( 'Sponsor Info',      'wordcamporg'  ), array( $this, 'metabox_sponsor_info'      ), 'wcb_sponsor',   'normal' );
 		add_meta_box( 'sponsor-agreement', __( 'Sponsor Agreement', 'wordcamporg'  ), array( $this, 'metabox_sponsor_agreement' ), 'wcb_sponsor',   'side'   );
 		add_meta_box( 'invoice-sponsor',   __( 'Invoice Sponsor',   'wordcamporg'  ), array( $this, 'metabox_invoice_sponsor'   ), 'wcb_sponsor',   'side'   );
+		add_meta_box( 'sponsor-notes',     __( 'Sponsor Notes',   	'wordcamporg'  ), array( $this, 'metabox_sponsor_notes'   ),   'wcb_sponsor',   'side'   );
 	}
 
 	/**
@@ -1806,6 +1807,11 @@ class WordCamp_Post_Types_Plugin {
 		require_once( __DIR__ . '/views/sponsors/metabox-invoice-sponsor.php' );
 	}
 
+	function metabox_sponsor_notes( $post ) {
+		$existing_notes = get_post_meta( $post->ID, '_wcbsponsor_notes', true );
+		require_once( __DIR__ . '/views/sponsors/metabox-notes.php' );
+	}
+
 	/**
 	 * Fired when a post is saved, makes sure additional metadata is also updated.
 	 */
@@ -1982,10 +1988,43 @@ class WordCamp_Post_Types_Plugin {
 					update_post_meta( $post_id, $meta_key, $value );
 				}
 			}
+
+			$this->validate_and_save_sponsor_notes( $post, $_POST['wcbsponsor_new_note'] );
 		}
 	}
 
 	/**
+	 * Validate and save expense data
+	 *
+	 * @param WP_Post $post
+	 * @param array    $expenses
+	 */
+	function validate_and_save_sponsor_notes( $post, $new_note_message ) {
+
+		$new_note_message = sanitize_text_field( wp_unslash( $new_note_message ) );
+
+		if ( empty( $new_note_message ) ) {
+			return;
+		}
+
+		$notes = get_post_meta( $post->ID, '_wcbsponsor_notes', true );
+		if ( ! is_array( $notes ) ) {
+			$notes = array();
+		}
+
+		$new_note = array(
+			'timestamp' => time(),
+			'author_id' => get_current_user_id(),
+			'message'   => $new_note_message
+		);
+
+		$notes[] = $new_note;
+
+		update_post_meta( $post->ID, '_wcbsponsor_notes', $notes );
+
+	}
+
+	/**
 	 * Registers the custom post types, runs during init.
 	 */
 	function register_post_types() {