Intervals API Resource:

invoice

The base URL for this resource is located at
https://api.myintervals.com/invoice/

There are two types of invoices:

Freeform invoices are blank invoices, and contain no line items initially. To add line items, you must create them through the invoiceitem resource.

Prefilled invoices are based on work performed, and on creation include line items based on time entries from the project to which the invoice belongs.

You can specify the type of invoice you want by using the datebegin and dateend fields. If you leave these fields blank, the invoice will be created as freeform. However, if you enter values for either of these fields, time entries will be imported from the invoice's project according to the date range you specify.

Once an invoice has been created, you cannot change the type of invoice it is, though you can add and edit line items no matter what the type (see the invoiceitem resource for more information about invoice restrictions).

If you have a prefilled invoice, you can rebuild it by changing either the datebegin or dateend field (or both). This has the effect of re-importing all time entries for your date range, while preserving any custom line items that your invoice may contain.

Collection

Allowed HTTP Methods
Method	Group Access
GET	Administrator, Manager, Executive

Allowed Filters
Filter Name	Required?	Expects	Default	Description
localid	no	integer¹		Restricts the list based on a invoice's "localid," which is the number that appears associated with the invoice in the Intervals application.
clientid	no	integer¹		Limits the list to invoices belonging to the client with the ID passed.
projectid	no	integer¹		Limits the list to invoices belonging to the project with the ID passed.
datebegin	no	date		Limits the list to expenses having a date on or after the date passed.
dateend	no	date		Limits the list to expenses having a date on or before the date passed.
status	no	string		Useful for specifying specific invoice statuses. Can be either "outstanding" or "paid".
search	no	string		Limits the list to invoices that match the search string.. Searches title, description, localid, purchase order and address fields.
sortfield	no	string		Sort the list by any of the following fields: id, projectid, date, title, description, localid, purchaseorder, project, client, datepaid, subtotal, total, payments, balance, datedue, daysoverdue, projectlabelid, projectlabel (sorted by project labels alphabeticaly), and projectabel_order (sorted by project label order in Settings & Defaults).
sortdir	no	string		Sets the sort direction of the returned list. Must be either "ASC" or "DESC".
offset	no	integer		Return invoices starting from the nth invoice.
limit	no	integer	10	Sets a limit to the amount of invoices returned in the response.

¹ Indicates that multiple values are allowed, in CSV format (e.g. "3,5,11,19").
² This field accepts HTML, but certain HTML elements may be stripped out.

Examples

To retrieve the entire list of this resource:

GET /invoice/

To filter the list based on certain parameters:

GET /invoice/?datebegin={value}

Note: You can string together multiple filters.

Member

Allowed HTTP Methods
Method	Group Access
GET	Administrator, Manager, Executive
DELETE	Administrator, Manager
POST	Administrator, Manager
PUT	Administrator, Manager

Settable Fields for PUT and POST Requests
Field Name	Required?	Expects	Default	Description
projectid	yes	integer
date	yes	date
termid	yes	integer
termother	no	string (255)		If you specify the termid as "other" (6), you can assign a custom term name to this invoice.
termotherdatedue	no	date		If you specify the termid as "other" (6), you must specify the custom due date of this invoice.
title	yes	string (255)		The invoice title.
description	no	string
addressfrom	no	string
addressto	no	string
purchaseorder	no	string (55)
tax	no	double
secondtax	no	double		For places with dual taxation levels, the value of the secondary tax level.
secondtaxcompound	no	boolean	f	For places with dual taxation levels, true if the second tax is compounded, false if the second tax is added.
disclaimer	no	string
datebegin	no	date		If you wish to create a pre-filled invoice based on work performed, set this to the start date of the time entries you wish to include.
dateend	no	date		If you wish to create a pre-filled invoice based on work performed, set this to the end date of the time entries you wish to include.

string (xxx) indicates a string with a maximum length of xxx characters.

Response Fields

The fields below are returned in GET responses. Boolean values are "t" / "f" strings. Numeric IDs and floats are returned as strings. Nullable fields may be JSON null.

Response Fields
Field Name	Nullable	Description
id	no	Unique identifier for the invoice
projectid	no	ID of the associated project
date	no	Invoice date (YYYY-MM-DD)
termid	no	ID of the payment term
termother	yes	Custom term text when using a non-standard term (empty when using a predefined term)
termotherdatedue	yes	Due date when using a custom term (empty when not applicable)
title	no	Invoice title
description	yes	Invoice description
localid	no	Human-readable invoice number / local ID (zero-padded)
addressfrom	yes	Billing address (from)
addressto	yes	Billing address (to)
purchaseorder	yes	Purchase order number
tax	yes	Primary tax rate or configuration (empty when none; often a string in JSON)
disclaimer	yes	Invoice disclaimer text
datebegin	yes	Work period start (invoiced range, YYYY-MM-DD) (Admin/Manager only)
dateend	yes	Work period end (invoiced range, YYYY-MM-DD) (Admin/Manager only)
second_tax	yes	Second tax rate or configuration (empty when dual tax not used)
second_tax_compound	yes	Second tax compound flag or value (empty when not applicable)
project	no	Name of the associated project
client	yes	Name of the associated client (empty when none)
clientid	yes	ID of the associated client (may be absent in some serializers; empty when none)
term	no	Human-readable payment term label (e.g. Net 90)
datepaid	yes	Date the invoice was fully paid (empty when unpaid)
subtotal	no	Invoice subtotal before taxes (May be returned as a string in JSON)
taxamount	yes	Computed primary tax amount (empty when none)
secondtaxamount	yes	Computed second tax amount (empty when none)
numitems	no	Count of line items on the invoice
total	no	Invoice total after taxes (May be returned as a string in JSON)
payments	no	Total payments applied to this invoice (May be returned as a string in JSON)
balance	no	Outstanding balance (total minus payments) (May be returned as a string in JSON)
datedue	yes	Invoice due date (YYYY-MM-DD)
daysoverdue	no	Days past the due date (0 when not overdue; often a string in JSON)
daysoverduepaid	yes	Days overdue before paid, or related paid-overdue metric (empty when not applicable)
status	no	Invoice status (e.g. overdue, paid — values depend on account)
projectlabel	yes	Name of the associated project label
projectlabel_order	yes	Sort order of the project label within the account
projectlabelid	yes	ID of the associated project label

Sample response object. Non-null values are strings in JSON (including IDs, numeric fields, and booleans as "t" / "f"). Nullable fields may be JSON null when absent.

{
    "id": "123456",
    "projectid": "123456",
    "date": "2026-01-15",
    "termid": "123456",
    "termother": "string value",
    "termotherdatedue": "2026-01-15",
    "title": "Example Title",
    "description": "Description text",
    "localid": "123456",
    "addressfrom": "string value",
    "addressto": "string value",
    "purchaseorder": "string value",
    "tax": "string value",
    "disclaimer": "string value",
    "datebegin": "2026-01-15",
    "dateend": "2026-01-15",
    "second_tax": "string value",
    "second_tax_compound": "string value",
    "project": "Project Name",
    "client": null,
    "clientid": null,
    "term": "Net 90",
    "datepaid": null,
    "subtotal": "1.5",
    "taxamount": "string value",
    "secondtaxamount": "string value",
    "numitems": "string value",
    "total": "1.5",
    "payments": "1.5",
    "balance": "1.5",
    "datedue": null,
    "daysoverdue": "string value",
    "daysoverduepaid": null,
    "status": "In Progress",
    "projectlabel": "Label A",
    "projectlabel_order": "1",
    "projectlabelid": null
}

When retrieving a collection (GET /invoice/), the response envelope includes: personid (authenticated user's ID), status ("OK"), code (200), listcount (total matching records before limit/offset), and invoice (array of result objects). Defaults, no cap on limit, and how to paginate using listcount are described in the API Introduction (Pagination).

Examples

To retrieve one member resource:

GET /invoice/{id}/

Assuming no errors, the server will respond with 200 OK and the object requested.

To delete a particular member resource:

DELETE /invoice/{id}/

Assuming no errors, the server will respond with 200 OK.

To create a new member resource:

POST /invoice/

{
    "projectid": value,
    "date": value,
    "termid": value,
    "title": value
}

Assuming no errors, the server will respond with 201 Created and the newly-created element. This will allow you to get the id of the item you just created and verify the field values. Note: Only required fields were listed here. The entire list of possible fields is above.

To update a member resource:

PUT /invoice/{id}/

{
    "tax": value,
    "dateend": value
}

Assuming no errors, the server will respond with 202 Accepted and the entire element. This will allow you to verify the field values.

Documentation

Resources

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OpenAPI

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