# Requirements - Folioline 1.x documentation

> The WordPress, WooCommerce and PHP versions Folioline needs, the PHP extensions for PDFs, what it works with, and where it keeps its data.

## Versions

| | Minimum |
|---|---|
| WordPress | 6.5 |
| WooCommerce | 8.2 |
| PHP | 7.4 (8.1 or later recommended) |

Folioline is tested with the latest WordPress and WooCommerce releases.

## PHP extensions for PDFs

PDFs need three PHP extensions that most hosts have: **gd** (images), **mbstring** (text) and **zlib** (compression). The **Download as ZIP** action also needs **zip**.

If one is missing, Folioline's screens say which. Invoices are still issued and numbered; their PDFs are made once your host adds the extension. Ask your host to turn it on.

## Works with

- **Checkout**: the Checkout block and the classic shortcode checkout. Both have the VAT number field, take VAT off for business customers straight away and show what the VAT number check said.
- **Order storage**: High-Performance Order Storage (HPOS) and the older posts storage.
- **Tax**: your tax rates stay in **WooCommerce → Settings → Tax**. Folioline prints what WooCommerce charged; it doesn't calculate tax itself.
- **Payment methods**: any. Unpaid orders, such as bank transfer or cash on delivery, get a due date and your bank details on the invoice.
- **Extendiment plugins**: Packboard, Returnline and Fieldline. See [Working with other plugins](working-with-other-plugins).
- **Outgoing connections**: the VAT number check asks VIES, the European Commission's service. The OSS report fetches the European Central Bank's published exchange rates when it needs them.

Folioline helps you issue correct invoices; it is not tax advice. What your invoices must show, and which rates apply, depends on your country: check with your accountant or tax office.

## Where Folioline keeps its data

- **Invoices and credit notes** in a database table of its own: one row for each, with its number and a frozen copy of everything it says. The number series are in a second table.
- **PDF and e-invoice files** in `wp-content/uploads/folioline/`, one folder per year. Web access to the folder is blocked: files reach people only through emails, My Account and the admin screens.
- **Orders**: the customer's VAT number, what VIES said, the consultation number, and the location evidence (IP address and its country) are order meta, so they stay with the order.
- **Settings** in one WordPress option, and the license in another.
- **VAT number rechecks** as scheduled actions in WooCommerce's Action Scheduler (**Tools → Scheduled Actions**, group `folioline`).

Orders always stay. Deleting the plugin can remove the rest: see [FAQ](faq).

## Multisite

Folioline can be activated per site or network-wide. Each site has its own invoices, number series, settings and license.

Source: https://extendiment.com/plugins/folioline/docs/1.x/requirements