Savings Plans or Reserved Instances: which should a team spending under £10k a month on AWS choose?

What are AWS Savings Plans and Reserved Instances?

Both are discounts in exchange for a commitment. With Savings Plans you commit to spend a fixed amount per hour on eligible usage for one or three years.

With Reserved Instances you commit to a specific type of instance or database for one or three years. In return, AWS charges less than on-demand prices.

How do Savings Plans and Reserved Instances compare?

Compute Savings Plans give up to 66% off with the most flexibility, EC2 Instance Savings Plans and Standard Reserved Instances up to 72% with less, and Database Savings Plans up to 35% on a one-year term.

Discounts depend on term, payment option and service, so check current AWS pricing for your exact usage before committing.

Should a small team choose Savings Plans or Reserved Instances for compute?

For most small SaaS teams, Compute Savings Plans are the right default.

They cover ECS on Fargate, EC2 and Lambda, and they keep applying if you move from one instance family to another or change regions. At small scale that flexibility is worth more than the few extra points of discount from EC2 Instance Savings Plans or Standard Reserved Instances, because your architecture is still changing.

Should a small team use Database Savings Plans or RDS Reserved Instances?

For databases you expect to resize or upgrade, Database Savings Plans, launched in December 2025, are usually the more flexible choice, but compare them with RDS Reserved Instances because the two cannot be combined on one workload.

Until December 2025, discounting RDS meant buying Reserved Instances for a specific instance class. AWS has since launched Database Savings Plans, which apply to eligible Aurora, RDS, DynamoDB, ElastiCache and other database usage regardless of engine, instance family, size or region, for up to 35% off with a one-year commitment. For a database you expect to resize or upgrade, that flexibility is useful. You cannot combine Database Savings Plans with RDS Reserved Instances for the same workload, so compare both before choosing.

How much should you commit to Savings Plans?

Commit to part of your lowest steady hourly spend over the last two or three months, after cleaning up waste, on a one-year term, and add more in small steps.

1. Clean up waste and rightsize first. Committing to waste locks it in.
2. Look at the lowest steady hourly spend over the last two or three months, not the average.
3. Commit to part of that steady baseline, leaving room for change.
4. Prefer one-year terms while your architecture is still evolving.
5. Review coverage and utilisation every month and add commitments in small steps.

AWS Cost Explorer shows Savings Plans recommendations based on your past usage. Treat them as a starting point, not an instruction.

When should you not commit to Savings Plans at all?

Do not commit while a migration is planned, while usage is still falling, when the saving is too small to matter, or when you are unsure the workload will exist in a year.

• You are planning a migration, such as moving from EC2 to Fargate or to a different database engine, and the coverage would not follow you.
• Your usage is still falling as you clean up waste.
• Your monthly spend is small enough that the saving does not justify the lock-in.
• You do not know whether the product or workload will exist in a year.

The monthly cost review checklist includes checking commitment coverage, so you can revisit the decision as usage settles.

Are you ready to buy an AWS commitment?

Tick each item before committing.

Do Savings Plans cover ECS on Fargate?

Yes. Compute Savings Plans apply to AWS Fargate as well as EC2 and Lambda.

That makes them a good fit for small teams running containers on ECS with Fargate, because the discount follows the workload if you change task sizes or move some services to EC2 or Lambda later.

What happens if you over-commit to a Savings Plan?

You pay the committed hourly amount whether you use it or not.

If usage falls below your commitment, the unused part is lost for that hour. That is why the safest approach is to commit to a part of your lowest steady usage, check utilisation each month, and add more in small steps rather than buying one large commitment.

Should you pay upfront for Savings Plans?

Paying all or part upfront gives a slightly larger discount than no upfront payment, but ties up cash.

For most early-stage SaaS companies, cash is worth more than the extra discount, so no upfront with a one-year term is a sensible default. Compare the options in the AWS pricing calculator before deciding.