diff --git a/public_html/wp-content/plugins/wordcamp-payments-network/includes/sponsor-invoices-list-table.php b/public_html/wp-content/plugins/wordcamp-payments-network/includes/sponsor-invoices-list-table.php
index 8a9f6d71c..f71b709a8 100644
--- a/public_html/wp-content/plugins/wordcamp-payments-network/includes/sponsor-invoices-list-table.php
+++ b/public_html/wp-content/plugins/wordcamp-payments-network/includes/sponsor-invoices-list-table.php
@@ -132,6 +132,7 @@ protected function column_amount( $index_row ) {
 	 */
 	protected function column_approve_invoice( $index_row ) {
 		$nonce = wp_create_nonce( "wcbdsi-approve-invoice-{$index_row->blog_id}-{$index_row->invoice_id}" );
+		$special_instructions = self::sponsor_has_special_instructions( $index_row->sponsor_name );
 
 		?>
 
@@ -144,11 +145,40 @@ class="wcbdsi-approve-invoice button-secondary"
 			Approve
 		</button>
 
-		<div class="wcbd-inline-notice hidden"><div> <?php // Populated dynamically ?>
+		<div class="wcbd-inline-notice hidden"></div> <?php // Populated dynamically ?>
+
+		<?php if ( $special_instructions ) : ?>
+			<p>
+				⚠️This sponsor has special payment instructions. Please <a href="https://make.wordpress.org/community/wordcamp-budgets-dashboard/#special-instructions">refer to the handbook</a> for details before approving.
+			</p>
+		<?php endif; ?>
 
 		<?php
 	}
 
+	/**
+	 * Determine if the sponsor has special invoicing instructions based on their name.
+	 *
+	 * This needs to be a fuzzy match, because the sponsor name is entered by the organizers, and may not be
+	 * consistent.
+	 */
+	protected static function sponsor_has_special_instructions( string $sponsor_name ) : bool {
+		$special_sponsors = array(
+			'GoDaddy',
+			'Google',
+			'WP Engine',
+			'WPEngine',
+		);
+
+		foreach ( $special_sponsors as $needle ) {
+			if ( false !== stripos( $sponsor_name, $needle ) ) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	/**
 	 * Render the value for columns that don't have a explicit handler
 	 *
diff --git a/public_html/wp-content/plugins/wordcamp-payments/includes/sponsor-invoice.php b/public_html/wp-content/plugins/wordcamp-payments/includes/sponsor-invoice.php
index 3e39709e6..aa7e50933 100644
--- a/public_html/wp-content/plugins/wordcamp-payments/includes/sponsor-invoice.php
+++ b/public_html/wp-content/plugins/wordcamp-payments/includes/sponsor-invoice.php
@@ -329,6 +329,7 @@ function render_sponsor_invoice_metabox( $post ) {
 	$selected_class_id    = get_post_meta( $post->ID, '_wcbsi_qbo_class_id',    true );
 	$selected_currency    = get_post_meta( $post->ID, '_wcbsi_currency',        true );
 	$description          = get_post_meta( $post->ID, '_wcbsi_description',     true );
+	$internal_reference   = get_post_meta( $post->ID, '_wcbsi_internal_reference', true );
 	$amount               = get_post_meta( $post->ID, '_wcbsi_amount',          true );
 
 	if ( 'add' === $current_screen->action && isset( $_GET['sponsor_id'] ) ) {
@@ -445,7 +446,7 @@ function save_invoice( $post_id, $post ) {
 	}
 
 	// Sanitize and save the field values.
-	$fields = array( 'sponsor_id', 'qbo_class_id', 'currency', 'description', 'amount' );
+	$fields = array( 'sponsor_id', 'qbo_class_id', 'currency', 'description', 'internal_reference', 'amount' );
 
 	foreach ( $fields as $field ) {
 		$meta_key = "_wcbsi_$field";
diff --git a/public_html/wp-content/plugins/wordcamp-payments/views/sponsor-invoice/metabox-general.php b/public_html/wp-content/plugins/wordcamp-payments/views/sponsor-invoice/metabox-general.php
index 86e4f17ff..e015a5d33 100644
--- a/public_html/wp-content/plugins/wordcamp-payments/views/sponsor-invoice/metabox-general.php
+++ b/public_html/wp-content/plugins/wordcamp-payments/views/sponsor-invoice/metabox-general.php
@@ -1,8 +1,22 @@
 <?php
 
 namespace WordCamp\Budgets\Sponsor_Invoices;
+use WordCamp_Budgets;
+
 defined( 'WPINC' ) or die();
 
+/**
+ * @var array  $available_sponsors
+ * @var array  $available_classes
+ * @var array  $available_currencies
+ * @var string $selected_sponsor_id
+ * @var string $selected_class_id
+ * @var string $selected_currency
+ * @var string $description
+ * @var string $internal_reference
+ * @var string $amount
+ */
+
 ?>
 
 <ul class="wcb-form">
@@ -94,6 +108,27 @@ class="regular-text"
 		<?php \WordCamp_Budgets::render_form_field_required_indicator(); ?>
 	</li>
 
+	<li>
+		<label for="_wcbsi_internal_reference">
+			<?php _e( "Sponsor's internal reference number:", 'wordcamporg' ); ?>
+		</label>
+
+		<div class="wcb-form-input-wrapper">
+			<input
+				type="text"
+				class="regular-text"
+				id="_wcbsi_internal_reference"
+				name="_wcbsi_internal_reference"
+				value="<?php echo esc_attr( $internal_reference ); ?>"
+				maxlength="75"
+			/>
+
+			<p class="description">
+				<?php _e( 'This is only necessary if the sponsor has asked you to include something specific on the invoice, like a PO or SCON number.', 'wordcamporg' ); ?>
+			</p>
+		</div>
+	</li>
+
 	<li>
 		<label for="_wcbsi_currency">
 			<?php _e( 'Currency:', 'wordcamporg' ) ?>
diff --git a/public_html/wp-content/plugins/wordcamp-qbo/wordcamp-qbo.php b/public_html/wp-content/plugins/wordcamp-qbo/wordcamp-qbo.php
index 97a516438..80c501aef 100644
--- a/public_html/wp-content/plugins/wordcamp-qbo/wordcamp-qbo.php
+++ b/public_html/wp-content/plugins/wordcamp-qbo/wordcamp-qbo.php
@@ -358,9 +358,15 @@ protected static function build_qbo_create_invoice_request( int $invoice_id ) {
 		$class_id      = sanitize_text_field( $invoice_meta['_wcbsi_qbo_class_id'][0] );
 		$amount        = floatval( $invoice_meta['_wcbsi_amount'][0] );
 		$description   = trim( sanitize_text_field( $invoice_meta['_wcbsi_description'][0] ) );
+		$internal_reference = trim( sanitize_text_field( $invoice_meta['_wcbsi_internal_reference'][0] ?? '' ) );
+
+		if ( $internal_reference ) {
+			$internal_reference = "Sponsor's internal reference: $internal_reference\n\n";
+		}
 
 		$statement_memo = sprintf(
-			'WordCamp.org Invoice: %s',
+			"%sWordCamp.org Invoice: %s",
+			$internal_reference,
 			esc_url_raw( admin_url( sprintf( 'post.php?post=%s&action=edit', $invoice_id ) ) )
 		);
 
@@ -428,6 +434,7 @@ protected static function build_qbo_create_invoice_request( int $invoice_id ) {
 		);
 
 		$payload = array(
+			// "Message on Statement" field in QBO.
 			'PrivateNote' => $statement_memo,
 
 			'CustomField' => array(
@@ -471,6 +478,7 @@ protected static function build_qbo_create_invoice_request( int $invoice_id ) {
 				'value' => $customer_id,
 			),
 
+			// "Message on Invoice" field in QBO.
 			'CustomerMemo' => array(
 				'value' => $customer_memo,
 			),