Walkthrough · article 15 of 18

Changing your tax rate
mid-year.

The right way to bump VAT without retroactively changing last quarter's P&L.

Ibrahim Ölmez Ibrahim ÖlmezFounder · nouz · 5 min read · Updated May 18, 2026
No retroactive effect. Changing your default tax rate today changes the suggested rate for new entries. Existing entries keep whatever rate they were logged with.

Tax rates change occasionally — governments adjust VAT, you cross a turnover threshold that bumps your rate, a specific product category gets reclassified. The right way to handle it in nouz is to update the default (or the specific product) going forward, and let the snapshot pattern protect your historical numbers.

01 How do I change my default tax rate?

Open Settings → Business profile, where the default tax rate is a field on the card. Edit it and click Save, and the new rate becomes the suggested value when you create a new product or a manual revenue entry — without touching anything you've already logged. The default is only a pre-fill, not the actual rate used: each product carries its own rate, and each manual entry takes a snapshot when saved. Changing the default only affects what future entries pre-fill with.

Worth noting: the default is just the suggested pre-fill, not the actual rate used. Each product has its own rate (which may already differ from the default). Each manual entry takes a snapshot at the moment it's saved. Changing the default only changes what future entries pre-fill with.

02 How do I change a single product's tax rate?

If a specific product's tax rate changes — a reduced rate increases, or a government policy shifts — open the product and edit its Tax rate field. From that moment, every new sale of that product uses the new rate, while past sales keep the old rate via the snapshot stored on each revenue entry. The same forward-looking pattern works for any per-product rate adjustment: the change applies going forward, and your history is preserved exactly as it was.

Same pattern works for any per-product rate adjustment: the change is forward-looking, history is preserved.

03 Do my past entries change when I update the tax rate?

No — past entries never change when you update a tax rate. This is the same no-retroactive rule that applies to product edits: every revenue entry stores a snapshot of its tax rate at the moment it was logged. Editing the default or a product's rate changes future entries only, never past ones, so your March P&L stays exactly as it was. The snapshot pattern protects your historical numbers automatically.

04 What if I genuinely need to fix a past tax rate?

If you really need to fix the past. Edit the individual revenue entry. The tax rate snapshot is on the entry itself — editing it there changes that one day's P&L. Most owners never need to, but the path exists.

When you genuinely need to fix a past tax rate, edit the individual revenue entry — the rate snapshot lives on the entry itself, so editing it there changes that one day's P&L. The real cases are rare: you logged a product at the wrong rate for an extended period, or your tax authority mandated a retroactive change and your accountant confirmed it should backdate. For typical mid-year rate changes, the snapshot pattern handles it cleanly with no past-data editing.

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