Annual Bonus affecting tax code

I have a annual bonus paid every year on May 1st. Last year it was a 8% bonus over my annual income. I have paid the taxes for those bonus as it is handle by my company. However, the month after, my tax code has changed and I paid more tax as it was considered that my income increased. How can I prevent it to happen this year? Thanks

Hi
Depending on your overall income, updating your code with a more accurate estimate of your expected income for the year may help.
To help us update your record with this estimate, contact us by webchat or phone via Income Tax: general enquiries