Yes. You can upgrade anytime in the app, and the upgrade starts straight away.
How to upgrade
Go to Profile > Settings > My Membership
Choose the plan you want
Tap Upgrade Plan and confirm
What happens when you upgrade
You only pay the difference. You get money back for the unused days of your old plan, and pay the new plan price minus that amount.
A new 4-week cycle starts that day. Your renewal date moves to the day you upgrade.
You get the new plan's full credits and bonus games. Unused plan credits from your old plan don't carry over.
Games you've already booked stay booked.
Pay-per-game credits are never touched.
Example
You're on Lite (€40 per 4 weeks) and upgrade to Smart (€60) with 7 of your 28 days left. Your unused Lite time is worth 7/28 × €40 = €10. You pay €60 − €10 = €50 today, and your new 4-week Smart cycle starts that day. This works on days left, not on how many games you played.
Tip: use your remaining plan credits before you upgrade, because they don't carry over.
Can't upgrade?
Membership paused: tap Resume membership first, then upgrade.
Account blocked for an unpaid invoice: pay the open invoice via the popup in the app first.
Yearly plans
Switching from a 4-week plan to a yearly plan, or to a higher yearly plan, works the same way: it starts straight away with a new yearly term, and you pay the difference. Going from yearly to a 4-week plan counts as a downgrade and starts when your yearly term ends.