> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gigstack.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Months and Bimesters Catalog (Meses y Bimestres)

> Integration guide for Months and Bimesters Catalog (Meses y Bimestres)

## Overview

In a Mexican global invoice, **`global.months` identifies the month or bimester**.
**`global.periodicity` identifies how frequently the period is grouped**. They are
separate SAT catalogs. For a monthly global invoice covering August, the fragment is:

```json theme={null}
{"global":{"periodicity":"04","months":"08","year":2026}}
```

This is an invoice-body fragment, not a complete request. See [Global invoices](/guides/catalogs/invoices_globals)
for the recipient and other required fields.

## What We See

`months` has 18 codes: `01`–`12` for named months and `13`–`18` for named bimesters.
Do not use a month code as the periodicity. For example, `periodicity: "01"` means
**daily**, not January, and `periodicity: "13"` is not a bimester periodicity code.

## How to Use It

Choose the reporting period that applies to the actual general-public sales and issuer.
Then provide the `months` code, numeric `year`, and separate `periodicity` code.
A subscription's billing interval does not by itself establish eligibility to issue a
global invoice or choose a two-month fiscal period.

## Periodicity Codes Table

This section lists **month and bimester codes for `global.months`**; its existing
section link is retained for older integrations. The separate periodicity codes
appear under [Global invoices](/guides/catalogs/invoices_globals#periodicity-codes-c_periodicidad).

### Individual Months (01-12)

| Code | Description (English) | Descripción (Español) | Calendar Period | Quarter |
| - | - | - | - | - |
| `01` | January | Enero | Jan 1 - Jan 31 | Q1 |
| `02` | February | Febrero | Feb 1 - Feb 28/29 | Q1 |
| `03` | March | Marzo | Mar 1 - Mar 31 | Q1 |
| `04` | April | Abril | Apr 1 - Apr 30 | Q2 |
| `05` | May | Mayo | May 1 - May 31 | Q2 |
| `06` | June | Junio | Jun 1 - Jun 30 | Q2 |
| `07` | July | Julio | Jul 1 - Jul 31 | Q3 |
| `08` | August | Agosto | Aug 1 - Aug 31 | Q3 |
| `09` | September | Septiembre | Sep 1 - Sep 30 | Q3 |
| `10` | October | Octubre | Oct 1 - Oct 31 | Q4 |
| `11` | November | Noviembre | Nov 1 - Nov 30 | Q4 |
| `12` | December | Diciembre | Dec 1 - Dec 31 | Q4 |

### Bimesters (13-18)

| Code | Description (English) | Descripción (Español) | Calendar Period | Months Covered |
| - | - | - | - | - |
| `13` | January-February | Enero-Febrero | Jan 1 - Feb 28/29 | 01, 02 |
| `14` | March-April | Marzo-Abril | Mar 1 - Apr 30 | 03, 04 |
| `15` | May-June | Mayo-Junio | May 1 - Jun 30 | 05, 06 |
| `16` | July-August | Julio-Agosto | Jul 1 - Aug 31 | 07, 08 |
| `17` | September-October | Septiembre-Octubre | Sep 1 - Oct 31 | 09, 10 |
| `18` | November-December | Noviembre-Diciembre | Nov 1 - Dec 31 | 11, 12 |

## Global Invoice Context

Global invoices group eligible sales to the general public; they are not a generic
way to combine identified customers' subscription invoices. Review the
[SAT's current global-invoice filling guide](https://www.sat.gob.mx/minisitio/Factura/emite_materialdeayudaparafactura.htm) for the permitted period,
issuer regime, receiver, and transaction details.

Daily and weekly periodicity codes exist. There is no blanket rule here that every
global invoice must cover an entire calendar month.

## Implementation Examples

### API Request Example

**Invoice-body fragment** for a daily global invoice in August:

```json theme={null}
{"global":{"periodicity":"01","months":"08","year":2026}}
```

**Invoice-body fragment** for a monthly global invoice in August:

```json theme={null}
{"global":{"periodicity":"04","months":"08","year":2026}}
```

The `global` object is accepted by [income creation](/reference/createInvoicesIncome)
and [draft creation](/reference/createInvoicesDraft). Fields such as `global_invoice`,
`period_year`, `start_date`, `end_date`, and `total_transactions` are not the public
API's global-invoice object.

### Validation Logic

Validate the three fields together before issuance. The input schema requires strings
for `periodicity` and `months`, and an integer for `year`; that type validation alone
does not establish fiscal validity. The provider applies fiscal rules when stamping.

## Common Use Cases

| Intended grouping | `global.periodicity` | `global.months` |
| - | - | - |
| Daily sales during August | `01` | `08` |
| Weekly sales during August | `02` | `08` |
| August monthly global | `04` | `08` |
| January–February bimester, when the issuer is eligible | `05` | `13` |

## Business Considerations

Confirm eligibility for the fiscal grouping before building a scheduler. Catalog
membership is not permission to use every periodicity under every regime. Keep
source sale/receipt references so excluded, individually invoiced, or already-grouped
sales can be reconciled.

## Important Notes

* `global.periodicity` uses SAT string codes `01`–`05`.
* `global.months` uses the month/bimester codes above.
* Team receipt settings use different words such as `day` and `month`; do not send those in `global.periodicity`.
* A global invoice uses the general-public recipient described in the [global guide](/guides/catalogs/invoices_globals#the-receiver), including `use: "S01"` in that flow.

## Error Prevention

If the provider rejects the period, inspect the actual `periodicity`, `months`, `year`,
issuer configuration, and issuance date. Do not change the month just to suppress an
error. On an ambiguous stamping response, reconcile the original attempt before retrying.

## Integration with Other Catalogs

Use [Global invoices](/guides/catalogs/invoices_globals) for the general-public customer fields,
[Usage](/guides/catalogs/usages) for `use`, and [Payment methods](/guides/catalogs/payment_methods) for timing.
The customer tax regime is distinct from the issuer's regime and does not authorize
a particular global-invoice schedule.

## Related Documentation

* [Global invoices](/guides/catalogs/invoices_globals)
* [Invoiceable receipt recipe](/recipes/receipt)
* [Cancellation of a global invoice](/guides/catalogs/cancellation_motives#global-invoice-conversion-workflow-motive-04)


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