Answers
Every question, answered.
The full question set behind Reserved Instances, renewals, coverage, and pricing: one page, one stable link per question. The same answers hold whether you're carrying one reservation or ten thousand.
Reservations, plainly
What a Reserved Instance actually is, the choices you make buying one, and the few ways AWS lets it flex.
- What exactly is an AWS Reserved Instance?
A Reserved Instance is a 1- or 3-year billing commitment that discounts matching usage automatically, not a reservation of physical capacity or a provisioning action. The discount applies the moment a running resource's attributes match the RI's, and stops the moment they don't. Reserver covers RIs for Amazon RDS, ElastiCache, and EC2 today. The only real risk is choosing the wrong term or class, or letting the term lapse unrenewed.
- What's the difference between a 1-year and 3-year term, and No/Partial/All Upfront?
Term (1 or 3 years) and payment option (No, Partial, or All Upfront) are the two levers that set how deep a reservation's discount goes. A longer term and more cash upfront both buy a deeper discount, but neither changes what's eligible to be reserved. A 1-year, No Upfront RI and a 3-year, All Upfront RI on the same instance class cover exactly the same usage, just at different prices and different cash-flow shapes. Which combination is worth it depends on how confident you are the instance family will still be running years from now, not on the discount numbers alone.
- Should I buy a 1-year or a 3-year reservation?
A 3-year term usually discounts more than a 1-year term. It also locks you in three times as long. AWS never cancels a Reserved Instance early: buy a 3-year term and stop the instance after 14 months, and you still pay for all 36. Run the numbers for your own instance type and horizon with the free Term Check tool.
- Should I pay All Upfront, Partial Upfront, or No Upfront?
All Upfront pays the whole term at purchase and reaches the deepest discount. No Upfront pays nothing at purchase and reaches the shallowest discount. Partial Upfront splits the two. Every option locks in the same non-cancellable term, so the choice is about cash flow, not risk.
- Does a reservation have to match the exact instance size we're running?
Not always, since size flexibility lets one reservation's discount apply proportionally across different sizes in the same instance family. EC2 Standard RIs get it at regional scope; RDS gets it on most engines, across Single-AZ and Multi-AZ; ElastiCache reserved nodes gained it in October 2024. What never flexes is the family itself. A reservation bought for the wrong family covers nothing, no matter how forgiving the size math is.
- Should we buy a Regional or a Zonal reservation?
Regional is the more flexible default, since its discount follows matching usage to any Availability Zone in the region. A Zonal RI pins the discount, and for EC2 a real capacity reservation, to one specific AZ, which only earns its keep when a workload genuinely can't tolerate an AZ-level capacity shortfall. For most fleets, Regional's flexibility is worth more than Zonal's capacity guarantee.
- Standard or Convertible: which Reserved Instance type should we buy?
Standard buys the deeper discount and fits a family with a stable track record; Convertible (EC2 only) trades some discount depth for the ability to exchange into a different family, size, OS, or tenancy mid-term. RDS and ElastiCache have no Convertible option at all, so on those two services the family and engine choice at purchase is final either way. A Standard RI can still be resold on the RI Marketplace if the fleet outgrows it; Convertible RIs can't.
Renewals & lapses
AWS Reserved Instances never renew themselves. What that costs, why it slips, and the one way out of a term early.
- What happens when a reservation I own expires?
Reserver tracks every reservation's end date. On Watch you get notified ahead of time with a renewal recommendation. On Autopilot, renewal purchases can happen automatically under the policy you set.
- Do AWS Reserved Instances renew automatically?
No, AWS Reserved Instances never renew themselves, on any of the three services Reserver covers. A renewal is a fresh purchase decision with its own term and payment option, and nothing in the AWS console prompts it. That's exactly why it slips even on disciplined teams: it's a calendar problem, not a technical one, and a calendar only works if someone or something is actually watching it.
- What does one missed renewal actually cost?
The median priced reservation in Reserver's own AWS Price List catalog is worth about $1,484 a year, so even a short lapse adds up fast. That's roughly $0.17 an hour, $4 a day, and $28 for a week left unnoticed, on a single reservation. Multiply by the number a fleet actually carries and a lapse of any length has a real price, whether it's the only one being tracked or one of thousands.
- Can we get out of a reservation we no longer need?
Only for EC2 Standard RIs: the RI Marketplace resells the unused portion of the term. Convertible RIs and every RDS or ElastiCache reservation have no resale option at all, so the safety valve exists for exactly one type on one service. It's a way out for a reservation bought against a family that turned out to be short-lived, not something to plan a purchase around from the start.
Coverage & how much to buy
The two numbers that tell you whether your reservations are doing their job, and the target that sits between under- and over-buying.
- What does "coverage" mean, exactly?
Coverage is the percentage of your reservable running capacity that's currently matched to a reservation you own. Anything below 100% is paying the on-demand premium on usage that could be discounted; coverage can't exceed 100%, so buying more reservations than there's reservable usage to match just leaves them sitting idle. It's measured only against usage that was ever eligible for a reservation in the first place, so the number stays honest rather than diluted by workloads that could never have been covered.
- Should we aim for 100% coverage?
Usually not: the right target sits below 100%, sized to the part of the fleet that's genuinely stable. Reserving every last instance leaves no room for the fleet to shrink, resize, or retire without paying for capacity that's gone. Most teams do better aiming for the steady core of the fleet and leaving the volatile edge on-demand, then revisiting the split as usage changes.
- Can a reservation actually cost more than just paying on-demand?
Yes, below a certain utilization, a reservation's own cost outweighs the discount it's providing, and it ends up losing money. That happens when the family it covers loses ground: it gets smaller, moves to a different region, or is decommissioned before the term ends, and the reservation goes on billing full price while discounting little or nothing. It's the failure mode coverage alone can't see, because coverage looks at the fleet's side of the equation, not the reservation's.
- Is there one number that tells us whether our reservations are actually working?
Effective Savings Rate (ESR) is that number: the percentage saved off on-demand-equivalent cost once coverage, discount depth, and utilization are all priced in. Two fleets can post the same coverage number and land on very different ESR, because discount depth and utilization move it just as much as coverage does. A renewal lapse shows up here too, priced in real points and dollars rather than hand-waved.
By fleet size
One account with ten reservations and an AWS Organization with ten thousand fail in different ways. Who owns the job, and what breaks first, at each size.
- I only have a handful of reservations, is Reserver worth it?
Usually, yes. Even a single reservation renewed a couple of weeks late typically costs more than a year of Reserver. Watch is free, forever. Autopilot is a flat $149 a month, or $1,490 billed once a year, whether you're tracking ten reservations or ten thousand. Small fleets get the same coverage map and expiry radar as anyone else.
- We run many AWS accounts. Does Reserver scale to that?
Yes, that's what Scale is for. Connect every account you run and see them all in one coverage map, for one flat $499 a month, or $4,990 billed once a year, covering every account. You connect each account individually today. We are still building one-stack AWS Organizations enumeration, SSO/SAML, and custom approval chains. Check the roadmap before you plan around them. Need an MSA, security review, or SLA on top of that? Enterprise handles the paperwork. Support for other clouds and AWS Savings Plans is on the roadmap, not shipping today.
- Who should own reservations when we only have 1–10, on a single account?
Usually nobody's dedicated job: it's a founder or the first platform hire tracking it alongside everything else. What breaks first is the renewal nobody put on a calendar: a term ends quietly, usage reverts to on-demand, and there's no dedicated owner to notice for weeks. Getting it wrong at this size is cheap in absolute terms but expensive next to the tool that would have caught it, and Watch, built for exactly this size, costs nothing.
- Who owns reservations once we have dozens across a few accounts?
Usually a platform or DevOps lead, with a finance counterpart reviewing the number on a schedule. What breaks first is the gap between reviews: coverage drifts in the weeks after a quarterly check closes, and nothing catches the difference until the next cycle. Getting it wrong at this size means a slow accumulation of small slippages across many reservations rather than one dramatic miss. It's harder to notice, and just as costly added up.
- Who owns reservations across an AWS Organization with hundreds or thousands?
Usually FinOps or cloud economics, with procurement and security weighing in on how access and approvals work. What breaks first is the seam between accounts: each one can look fully covered in isolation while the org-wide picture hides a much bigger gap, and re-orgs strand reservations tied to a team or account that no longer exists. Getting it wrong at this size is invisible per account and very real in aggregate. The money hides exactly where no single dashboard looks.
- How much time does this actually save?
A Growth-size fleet spends about 39 hours a year tracking reservations by hand. That's $3,705 at a fully loaded rate, split across quarterly reviews, cross-account reconciliation, and purchase decisions. That's about 2× what Autopilot costs a year. Reserver reclaims most of that time. Somebody still approves the purchases.
- Does a Reserved Instance discount apply across all my AWS accounts?
Yes, by default: AWS shares a Reserved Instance or Savings Plans discount with every account on the same consolidated bill, not just the account that bought it. That is why a per-account coverage number can be wrong in either direction. The discount your account is measuring might belong to a reservation sitting in a different one. A Zonal RI is the one exception; it never shares. Left unnoticed for a month, one reservation's lost discount costs about $403, at the same illustrative on-demand rate used elsewhere on this site.
Pricing & value
Flat price, every tier, unlimited reservations. What that means for the bill and how fast it pays for itself.
- Do you take a percentage of my savings?
No, never. Reserver is a flat price, billed monthly or annually. Percentage-of-savings pricing means your vendor profits most when your bill was worst. We'd rather just charge for the software.
- We already use Cost Explorer's recommendations. Why Reserver?
Cost Explorer tells you a number and leaves you to reconcile it across three consoles. Reserver matches every reservation to a running instance, shows its work, flags the gaps and expiries, and then makes the purchase a button, or a rule.
- Is Watch really free forever, or is that an early-access price?
Forever. Watch covers one AWS account, unlimited reservations, and the full coverage map and expiry radar. It's not a trial and not a promotion that expires. You only pay if you outgrow it and want automated purchasing across more accounts.
- Do you charge per reservation, or per instance?
No. Every Reserver plan covers unlimited reservations, from one to tens of thousands. Pricing scales with connected AWS accounts and automation depth, never with how many reservations you have or how much you save.
- What happens to our price when we connect more AWS accounts?
Nothing changes until you cross a plan's account limit. Watch covers 1 account, Autopilot up to 5, and Scale covers an unlimited number for one flat $499 a month, or $4,990 billed once a year. You add each account yourself today, and one-stack AWS Organizations enumeration is on the roadmap. No per-account surcharge, no renegotiation.
- Why is Enterprise still a custom quote instead of a published price?
Because it isn't a bigger version of Scale. It's Scale plus the paperwork some procurement teams require before anyone connects an account: a master service agreement, a security review, an SLA with a named contact, and private commercial terms. Those vary enough by customer that a single number would either overcharge most of them or undercharge the rest.
- How fast does Reserver actually pay for itself?
Fast enough that a single missed renewal usually costs more than the tool itself: on the growth-fleet numbers used elsewhere on this site, Autopilot's flat $149/month typically pays for itself in about 7 days. That figure moves with your own spend and coverage, which is why the savings calculator on the pricing page runs the same math against a number you type in rather than a stock example. Watch has no payback period to clear in the first place: it's free.
Security, access & procurement
What the read-only role can see, what the purchase role can touch, and what procurement asks for before either gets connected.
- Does Reserver need write access to my AWS account?
Not to watch. The Watch plan uses a read-only IAM role limited to Describe/List calls for RDS, ElastiCache, and EC2. Purchasing on Autopilot uses a separate, tightly-scoped role that can buy reservations and nothing else. It cannot touch your workloads, data, or networking. More in our security model.
- What can the read-only role actually do?
Nine named Describe/List calls, for RDS, ElastiCache, and EC2. No service-wide wildcards. It can read the shape of your fleet: instance types, regions, tags, reservation details, and nothing else. It cannot start, stop, modify, or delete anything.
- What can the purchase role actually do?
It's a separate role scoped to the AWS reservation purchase APIs: rds:PurchaseReservedDBInstancesOffering and equivalents for ElastiCache and EC2. It cannot touch your running workloads, your data, or your networking.
- Can Reserver see our data, not just our infrastructure metadata?
No. Reserver reads infrastructure metadata used for matching: instance classes, regions, engines, reservation terms. Never database contents, cache values, or application data.
- Is our data isolated from other customers?
Yes. Every record is scoped to your organization; cross-organization access isn't a permissions check that can be misconfigured; it simply returns not-found.
- How do you access our AWS accounts? Do you store credentials?
Cross-account access is assume-role only, using the role you created and can revoke. We never see or store your AWS access keys.
- Can something buy a reservation without our sign-off?
Only if you set it up that way. Watch-only mode never buys anything. On Autopilot, every rule can require an approval step before a purchase executes, and every purchase, manual or automatic, is logged with who, what, and when.
- Are you SOC 2 or ISO 27001 certified?
Not yet. Reserver is pre-launch. Formal certifications are on the roadmap; we'd rather say that plainly than claim something we can't back up.
- Do the free tools upload our data anywhere?
No, every free tool parses, matches, and prices what you paste entirely in your browser. The Coverage Check fetches one small, public price list from this site on your first Analyze. Every other free tool, including the Expiry Check, makes no network request at all. Nothing typed or pasted into any of the seven free tools is ever sent to a server, and none of them need a signup to use.
Scope & roadmap
RDS, ElastiCache, and EC2 ship today. Savings Plans, OpenSearch, Redshift, and other clouds are the honest roadmap, not a claim about today.
- Can Reserver buy reservations for me today?
Not yet. Reserver already finds the recommendation and shows the math. It does not execute the purchase today. Reserver is still building one-click purchasing, renewal autopilot, scheduled purchases, and age-based rules. We ship the read-only product well first, on purpose. See what is live and what is next on the roadmap.
- Which AWS services are covered?
Reserved Instances for Amazon RDS, ElastiCache, and EC2 at launch. Savings Plans, OpenSearch, Redshift, and other reservable services are on the roadmap.
- Does Reserver work with Azure or Google Cloud?
Not today. Reserver covers Reserved Instances for Amazon RDS, ElastiCache, and EC2, with Azure and Google Cloud on the roadmap, not shipping. It matters more than it might seem: Azure reservations auto-renew by default and Google Cloud's resource-based CUDs are opt-in, while AWS has no auto-renewal at all. A habit learned on either of the other two clouds is exactly backwards on AWS. See our multi-cloud renewal comparison for the vendor-sourced breakdown.
- Does Reserver support AWS Savings Plans?
Not yet: Savings Plans are on the roadmap, not shipping today. A Savings Plan is a spend-based commitment rather than an instance-shaped one, so it needs its own matching logic rather than reusing an RI's. We'd rather ship RIs for RDS, ElastiCache, and EC2 well than claim Savings Plans support before it's real.
- What about OpenSearch or Redshift reservations?
Not yet: Reserved Instances for Amazon RDS, ElastiCache, and EC2 ship today; OpenSearch and Redshift are on the roadmap. Both have their own reservation mechanics that need the same care the first three services got before they're worth shipping. If either is holding up a decision to connect an account, the waitlist is the way to hear when it lands.
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