What should I do if the patent annual fee payment deadline has expired?

Expired within 6 months to 2 years: need to be treated individually by individual countries to see if the rights can be restored with the relief measures allowed by this country;

Overdue for less than 6 months: Most countries have a 6-month grace period for annual fee payment. If it is still within the 6-month period, you only need to pay the penalty within the grace period, plus the annual fee for the current year. .