Tax Groups (VAT codes)
Tenant-managed VAT codes in Omnium — a rate, an ERP/SAF-T external code (MVA-kode), validity windows for rate changes, and how tax groups tag products, prices, and ledger lines.
A tax group is a tenant-defined VAT code: a short stable identifier carrying a VAT rate and an external code (the ERP / SAF-T MVA-kode) that your accounting system uses on a VAT return. Tax groups tag products, prices, and order lines, and that tag flows through to the VAT code and rate on each ledger line.
Tax groups are managed under Tenant Settings → Accounting → VAT rates.
The tax-group subsystem is an independent switch from posting generation. You can enable VAT-coded settlement reports without turning on full postings, and vice versa. While the switch is off, nothing reads tax-group fields and behaviour is unchanged.
Why tax groups exist
A bare VAT rate (25) is not enough for accounting. Two lines can both be 0 % yet need different treatment — zero-rated (within VAT scope, reported) versus outside VAT scope (not reported as VAT at all). A tax group attaches the rate and the ERP code and the scope flag to a single tenant-chosen code, so the distinction survives all the way to the VAT return.
Tax group fields
| Field | Required | Description |
|---|---|---|
| Code | ✓ | Short stable identifier referenced by products, prices, and lines (e.g. HIGH, FOOD, OUTSIDE). Unique within the chart. |
| Name | ✓ | Display name shown in the UI (e.g. Standard 25%, Næringsmidler 15%). |
| Description | Optional longer note. | |
| Rate | ✓ | VAT rate as a percentage — 25 for 25 %, 11.11 for 11.11 %, 0 for zero-rated. |
| External code | The ERP / SAF-T tax code (Norwegian MVA-kode such as 3, 33, 6). Free text — each ERP and country differs. Flows onto the ledger line's VAT code and into CSV settlement exports. | |
| Outside VAT scope | Mark groups that represent activity outside the VAT system (no VAT applies), so reporting can distinguish them from a genuine 0 % rate. | |
| Valid from / Valid to | Inclusive validity window (date only). Used to handle government rate changes — see below. | |
| Active | Inactive groups are not selectable. Defaults to on. |
A group may optionally override the sales or output-VAT GL account directly, for the rare case where the Chart of Accounts can't express a per-group account. Normally these are left blank and the account is resolved through the chart.
Validity windows and rate changes
When a government changes a VAT rate, you do not edit the existing group in place. Instead, introduce a new entry with the same code and the new effective Valid from date, and set the old entry's Valid to to the day before. Omnium resolves the group valid on each posting's accounting date, so historical postings keep the rate that was in force when the sale happened and new postings pick up the new rate automatically.
Validity windows for the same code must not overlap — an overlap is ambiguous and is reported by the Validation tab.
Default tax group
When tax groups are enabled, a default tax group code must be set. It is applied to any product, price, or line that doesn't specify its own group. The default must reference a currently-active group.
How a line gets its tax group
The tax group on a ledger line is resolved from the most specific source available — a line-level tag, then the product's tax group, falling back to the tenant default. Products carry an optional tax group code (and a snapshotted tax rate), so the rate in force at the time of sale is captured even if the group's rate later changes.
Presets
Omnium ships starter charts for common markets that you can apply and then adjust. You must verify every external code against your own ERP's MVA-kode chart — the presets use commonly-used codes but every ERP differs.
Norway
| Code | Name | Rate | External code |
|---|---|---|---|
HIGH | Standard 25% | 25 | 3 |
MID | Lav sats 12% | 12 | 33 |
FOOD | Næringsmidler 15% | 15 | 31 |
FISH | Råfisk 11.11% | 11.11 | 32 |
ZERO | Fritatt for mva (0%) | 0 | 5 |
EXPORT | Eksport (0%) | 0 | 52 |
OUTSIDE | Utenfor mva-loven | 0 (outside scope) | 6 |
PANT | Pant (statsavgift) | 0 (outside scope) | — |
PANT represents a bottle/container deposit — a statutory deposit, not VAT — and should be mapped to its own GL account.
Sweden
| Code | Name | Rate | External code |
|---|---|---|---|
HIGH | Standard 25% | 25 | MP1 |
MID | Livsmedel 12% | 12 | MP2 |
LOW | Böcker, transport 6% | 6 | MP3 |
ZERO | Momsfri (0%) | 0 | MF |
EXPORT | Export (0%) | 0 | EX |
Related pages
- Postings & Ledger Lines — how sales and VAT are split per rate and tagged with the group's code.
- Chart of Accounts — bind a chart entry to a tax group, and per-group account overrides.
- Configuration — enabling tax groups and the default group.