iban

The widget extends the standard char field and adds a debounced validator:

this.validateIbanDebounced = useDebounced(async (ev) => {
    const iban = ev.target.value;
    if (!iban) {
        this.state.isValidIBAN = null;
    } else if (!/[A-Za-z]{2}.{3,}/.test(iban)) {
        this.state.isValidIBAN = false;
    } else {
        this.state.isValidIBAN = await this.orm.call(
            "res.partner.bank", "check_iban", [[], iban]);
    }
}, DELAY);

Three branches, three states. Empty gives null, meaning unknown rather than wrong, so an untouched field is not marked red. A value failing the local pattern is rejected immediately with no server call. Anything else goes to the server, which does the real checksum validation.

DELAY is exported as 400 milliseconds, which is long enough that typing a full IBAN produces a single call.

A wrong bank account number is one of the more expensive data errors in an ERP, because it is discovered at payment time. Validating while the user types moves that discovery to the moment of entry.

The design choice worth noting is that real validation happens on the server. The browser only filters out obvious nonsense. That keeps the checksum rules in one place and means the widget cannot be tricked into approving something the server would reject.

If you are running Odoo 19 with this on your bank account forms, be aware that an Odoo 20 upgrade removes it, and the visible symptom is simply that the indicator stops appearing.

On a bank account field in Odoo 19:

<field name="acc_number" widget="iban"/>

In Odoo 20 there is no registration to resolve, and the field renders as a plain char with no validation.

Most removed widgets leave their server side behind. This one did not, and that makes the removal deeper than it first appears.

On the client, addons/base_iban/static/ does not exist on the 20.0 branch. The module is still there, but it contains only models/. There is no JavaScript at all.

On the server, check_iban is defined in Odoo 19 at addons/base_iban/models/res_partner_bank.py. Searching the entire Odoo 20 source tree for that name returns no .py file, only a stale compiled cache artifact left over from an earlier build. So the method the widget called is not part of the Odoo 20 source either.

That matters for anyone planning a workaround. Reimplementing the widget as a custom component will not work by itself, because there is no server method left to call. A custom solution on Odoo 20 needs both halves: a component and a validation method of your own, or a Python library doing the checksum.

Worth being precise about what we can and cannot say. We verified that the widget and the method are absent from the 20.0 source. We did not find a documented replacement, and we are not going to guess at one. If Odoo has moved IBAN validation somewhere we have not found, we will correct this page and say so.

Removed. The iban registration does not exist on the 20.0 branch, and the entire static/ folder has been deleted from base_iban, leaving a Python-only module.

The check_iban method the widget depended on is also absent from the Odoo 20 Python source. A view carrying widget="iban" will log a missing-widget warning and render the field as a plain char.

If live IBAN validation matters to your finance process, treat this as work to scope rather than a setting to restore.