Yes! There's no commitment to stay on any plan and you can change each month as your needs fluctuate.
When you change to a higher plan you will be immediately upgraded and have access to the benefits of the higher tier. So if you have hit your coverage limit for the month but want to continue uploading, just upgrade for immediate access to the higher limit. You'll pay the difference between your current and new plan.
When downgrading, you will retain your current plan until your renewal date. This means you can downgrade at any time to switch your plan when you renew.
If you only need the higher plan for a single month, just downgrade again after your upgrade goes through and you will move back to your original plan again at your next billing date.
If you're upgrading a monthly plan regularly during busier periods, switching to annual billing is less hassle and more flexible. You'll get a discount, plus all the year's usage is available any time so its great for busier months here and there. Check out our annual plans here