> ## Documentation Index
> Fetch the complete documentation index at: https://docs.seosorted.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Sites and add-ons

> Buying more sites, raising your article limit, and the add-ons that work on any plan.

Sites are what you are billed for. Add-ons raise a single allowance on a single site.

## Sites

Each site is a separate project: its own keywords, articles, audits and connected CMS. One is
included with Pro, and you can cover up to 20.

Adding a site takes effect immediately and is prorated — you pay for the part of the month
you actually use.

<Note>
  Releasing a site is different: see [Changing your plan](/billing/changes). It takes effect at
  the end of the period you have already paid for, and the project is archived rather than
  deleted.
</Note>

## Add-ons

<CardGroup cols={3}>
  <Card title="Additional articles" icon="file-lines">
    Raises one site from 30 articles a month to **60** or **90**. Requires Pro.
  </Card>

  <Card title="Image presets" icon="palette">
    Custom brand image styles, generated on your own presets. Requires Pro.
  </Card>

  <Card title="Backlinks" icon="link">
    Directory submissions that build referring domains. **Works on any plan**, including Free.
  </Card>
</CardGroup>

Add-ons attach to **one site**, not to your whole account. Two sites that both need 90
articles a month need the add-on twice.

### Tiers replace, they don't stack

This is the part people expect to work the other way.

Moving from the 60-article tier to the 90-article tier gives you **90 articles a month**, not
150\. The tier *is* your new allowance — it replaces what the plan gives you rather than adding
to it. The same is true in reverse: dropping to a smaller tier lowers your allowance to that
tier's number.

You always hold at most one of each add-on per site, so there is no way to accidentally buy
two and pay twice.

### Backlinks is independent

Backlinks is the one add-on that does not require Pro. A Free account can buy it, stays on the
Free plan, and gets backlink credits and nothing else. If you later cancel Pro, your backlinks
package is untouched — it never depended on Pro in the first place.

## Seeing the price before you commit

Every add-on purchase and site change shows you the exact amount first, taken from Stripe
rather than estimated.

<Warning>
  This matters most on the annual plan. Adding an add-on two months into a year produces a
  large prorated line, because you are buying the remaining ten months at once. The amount is
  correct — check it before confirming.
</Warning>

## Changing your billing interval

Switching from monthly to annual applies straight away, prorated.

Switching from annual back to monthly is scheduled for your renewal date instead. Doing it
mid-year would mean crediting most of a year and re-billing a month, which is a refund
wearing a costume — so we wait for the year you paid for to finish.