How long your transaction records stay in the database. There is a right answer, and it is probably not the one you would guess.
Where
Go to Mollie Payments, then the Options tab, and find Data retention (GDPR).
The setting
Retain transactions for, in months.
The plugin tells you what the law expects: EU tax law typically requires 60 months, which is five years.
What actually gets deleted
Read this carefully, because it is more careful than it sounds.
After the period you set, completed transactions are removed automatically each night. Completed means paid, failed, canceled, expired or refunded.
Pending transactions are never deleted automatically. A pending payment is unfinished business, and the plugin will not quietly throw it away.
What to set
Sixty months. Unless you have specific advice from your accountant saying otherwise, this is the answer.
It is what EU tax law expects, and having to explain to a tax inspector that you deleted your records early is a conversation nobody wants.
The tension, honestly
GDPR says do not keep personal data longer than you need it. Tax law says keep your records for five years.
These are not actually in conflict, because tax law is the reason you need it. Keeping payment records for five years is lawful, expected, and defensible.
Keeping them for fifteen years because you never thought about it is a different matter. Which is why the setting exists.
This is not legal advice
We build payment software, not law. If you operate outside the EU, or you have unusual requirements, ask someone qualified.
What we can tell you is what the plugin does, and it does exactly what the setting says.