# Buying & renewing

This page covers the mechanics of paying for OpenAlex: how to buy, how billing works, and the answers to the purchasing questions we get most. For what you're buying, see the [Pricing overview](/access/pricing/).

## Buying prepaid usage

Prepaid usage is self-serve: log in and buy it directly on the [pricing page](https://openalex.org/pricing), in $1 increments, by card. At checkout you can request a **company/VAT invoice** — you'll be asked for your billing address and (optional) VAT/Tax ID so the invoice can be addressed to your company.

Prepaid usage is drawn down only after your free $1 daily budget runs out, and it **expires 3 months after your most recent purchase** — each new purchase refreshes the clock for your whole balance.

## Buying an annual plan

Annual plans ([Member, Member+, and Partner](/access/pricing/#annual-plans)) are sold by our team, not self-serve — most subscribers are institutions that need quotes, purchase orders, and invoices. Email [sales@openalex.org](mailto:sales@openalex.org) and we'll find the right plan, provide a quote, and invoice your organization. The [PDF sync add-on](/access/pricing/#the-pdf-sync-add-on) is scoped the same way, as part of your plan.

## Trials

We aren't able to offer free trials of the annual plans at this time. Remember that the free tier and prepaid usage let you evaluate the API itself at full fidelity before committing — the plans change your budget and benefits, not the product. If you have questions about your institution's needs, [sales@openalex.org](mailto:sales@openalex.org) is happy to talk it through.

## Renewing

Plans run for one year and **renew automatically** each year — you don't need to do anything to stay subscribed. To change tiers, add the PDF sync service, or cancel your renewal, email [sales@openalex.org](mailto:sales@openalex.org). If you're on an older Premium or Institutional contract, see [Legacy plans](/access/legacy-plans/) for how renewal works.

## When your budget runs out

If you exhaust your free daily budget (and any prepaid usage), API requests return a rate-limit error until your budget resets at midnight UTC. You can wait for the reset, buy prepaid usage anytime to keep going, or — if this happens often — consider an [annual plan](/access/pricing/#annual-plans).

## Getting an API key

Just create a free OpenAlex account — you get an API key automatically, with $1/day of free usage and no payment method required. See [Authentication](/api/authentication/).