If you're already subscribed and want to switch plans, the amount charged depends on:
whether you're changing your billing cycle (monthly ↔ yearly), and
whether you're changing to a different plan tier (for example, Pro → Premium).
In general, Heptabase will always account for the unused value of your current subscription when you switch plans.
How to switch
For a tier upgrade (Pro → Premium/Premium+, or Premium → Premium+), open the in-app plan selection and choose your target tier and monthly or yearly billing. Review Total due today before confirming. The change takes effect immediately, and any amount due is charged when you confirm.
For a downgrade or a monthly/yearly switch within the same tier, go to Settings → Subscription → Manage Subscription and review the change in the billing portal.
Account balance credits can reduce Total due today to $0. In that case the plan can still change immediately without a payment; any remaining account credit is kept for future charges. Account balance credits are separate from AI credits.
Important: Plan changes are blocked when your current subscription is past due or has an open unpaid invoice. The upgrade preview may still open, but confirmation is refused; the billing portal restricts plan changes while you resolve the payment. Pay or resolve the outstanding invoice first, or contact support. A separate unpaid on-demand invoice alone does not trigger this subscription plan-change block.
Before you confirm the change, Stripe will usually show an estimated charge amount. You can click View details to see how the amount is calculated.
Keep the same billing cycle
If you keep the same billing cycle (monthly → monthly or yearly → yearly), your billing cycle does not restart.
The amount due is the remaining cost of the new plan minus the unused value of your current plan.
So if you're switching from Pro yearly to Premium yearly halfway through your subscription, you won't be charged the full annual Premium price right away. You'll only pay the difference for the remaining time left in your current billing period. At your next renewal date, you'll then be charged the full price of the new yearly plan.
Example
If your current yearly subscription renews on December 2, and you switch from Pro yearly to Premium yearly on April 2, you'll pay roughly:
the Premium price for April 2 to December 2
minus the unused Pro value for April 2 to December 2
That means the amount due now is often much lower than the full annual price.
Change your billing cycle
If you change billing cycles (monthly → yearly or yearly → monthly), a new billing period starts immediately.
However, it still takes into account the unused value of your old subscription and applies that value before charging you.
Monthly → Yearly
When switching from monthly to yearly:
your yearly subscription starts immediately
your next renewal date is recalculated from the day you switch
the unused portion of your monthly subscription is automatically applied toward the yearly price
So you are not paying both full prices. The remaining value of your monthly plan is deducted from the amount due.
Example
If you recently paid for a monthly plan and switch to yearly after only a few days, the unused part of that month is converted into value and deducted from the yearly plan, so the amount you pay now is lower than the full yearly price.
Yearly → Monthly
You can switch from yearly to monthly, but there are two important things to know:
your billing cycle will restart immediately
the unused portion of your yearly plan will not be refunded as cash
Instead, the unused value of your yearly subscription is converted into credits, and those credits will automatically be used for future monthly renewals. These credits cannot be exchanged for cash.
This is why, after switching from yearly to monthly, you may see a new monthly billing date appear much sooner than your original yearly expiration date. The remaining yearly value hasn't disappeared — it has been converted into credits that will be consumed by future renewals.
How account credits work
When a switch creates unused subscription value, that value may appear as credits.
Credits:
are automatically applied to future subscription charges
are not paid out as cash
may explain why your next bill is lower, delayed, or fully covered
In some cases, users may not directly see the full internal credit breakdown, but the credits are still used by the billing system when future renewals happen.
Get help with a charge
Before confirming a plan change, Stripe usually shows an estimated amount and lets you open View details for a breakdown. If you're unsure how to interpret that amount, please contact support and share a screenshot of the billing page before completing the switch.
Important: If you accidentally chose a yearly plan and need immediate help switching to monthly, please contact support for assistance.