To change or set your deposit limits, go to My Account and select the Responsible Gaming section.
Enter the amount you want to limit yourself to per day, week or month, and select Submit. Then you need to confirm the new limits.
The limits apply on a rolling basis (last 24 hours, last 7 days, last 30 days) and the lowest applicable limit always applies (for example if your limits are at 100 per day and 50 per week, the maximum you can deposit is 50).
You can always lower your limits, but if you wish to increase them, that will only take effect 7 days after you placed your increase request.