diff --git a/client/state/login/test/utils.js b/client/state/login/test/utils.js
new file mode 100644
index 0000000000000..f03d0eba2fa82
--- /dev/null
+++ b/client/state/login/test/utils.js
@@ -0,0 +1,44 @@
+import { isPartnerSignupQuery } from '../utils';
+
+describe( 'isPartnerSignupQuery', () => {
+	it( 'should return false when currentQuery is undefined', () => {
+		const result = isPartnerSignupQuery( undefined );
+		expect( result ).toBe( false );
+	} );
+
+	it( 'should return false when currentQuery is null', () => {
+		const result = isPartnerSignupQuery( null );
+		expect( result ).toBe( false );
+	} );
+
+	it( 'should return true when currentQuery has is_partner_signup', () => {
+		const currentQuery = { is_partner_signup: true };
+		const result = isPartnerSignupQuery( currentQuery );
+		expect( result ).toBe( true );
+	} );
+
+	it( 'should return true when currentQuery has redirect_to with partner-signup', () => {
+		const currentQuery = { redirect_to: 'https://woocommerce.com/partner-signup' };
+		const result = isPartnerSignupQuery( currentQuery );
+		expect( result ).toBe( true );
+	} );
+
+	it( 'should return true when currentQuery has oauth2_redirect with partner-signup', () => {
+		const currentQuery = { oauth2_redirect: 'https://woocommerce.com/partner-signup' };
+		const result = isPartnerSignupQuery( currentQuery );
+		expect( result ).toBe( true );
+	} );
+
+	it( 'should throw an error when an unexpected error occurs', () => {
+		const currentQuery = { redirect_to: 'https://woocommerce.com/partner-signup' };
+		const originalDecodeURIComponent = global.decodeURIComponent;
+		global.decodeURIComponent = jest.fn( () => {
+			throw new Error( 'Unexpected error' );
+		} );
+
+		expect( () => isPartnerSignupQuery( currentQuery ) ).toThrow( 'Unexpected error' );
+
+		// Restore the original decodeURIComponent function
+		global.decodeURIComponent = originalDecodeURIComponent;
+	} );
+} );
diff --git a/client/state/login/utils.js b/client/state/login/utils.js
index f12c932ce1ca4..52ca29ffc1e75 100644
--- a/client/state/login/utils.js
+++ b/client/state/login/utils.js
@@ -190,18 +190,27 @@ export function isPartnerSignupQuery( currentQuery ) {
 		return true;
 	}
 
-	// Handles login through /log-in/?redirect_to=...
-	if ( typeof currentQuery?.redirect_to === 'string' ) {
-		return /woocommerce\.(?:com|test)\/partner-signup/.test(
-			decodeURIComponent( currentQuery.redirect_to )
-		);
-	}
+	try {
+		// Handles login through /log-in/?redirect_to=...
+		if ( typeof currentQuery?.redirect_to === 'string' ) {
+			return /woocommerce\.(?:com|test)\/partner-signup/.test(
+				decodeURIComponent( currentQuery.redirect_to )
+			);
+		}
 
-	// Handles user creation through /start/wpcc?oauth2_redirect=...
-	if ( typeof currentQuery?.oauth2_redirect === 'string' ) {
-		return /woocommerce\.(?:com|test)\/partner-signup/.test(
-			decodeURIComponent( currentQuery.oauth2_redirect )
-		);
+		// Handles user creation through /start/wpcc?oauth2_redirect=...
+		if ( typeof currentQuery?.oauth2_redirect === 'string' ) {
+			return /woocommerce\.(?:com|test)\/partner-signup/.test(
+				decodeURIComponent( currentQuery.oauth2_redirect )
+			);
+		}
+	} catch ( e ) {
+		if ( e instanceof URIError ) {
+			// Ignore the URIError
+			return false;
+		}
+		// Should not happen, re-throw the error
+		throw e;
 	}
 
 	return false;