---
title: "Integrations - Fastbill"
url: "https://docs.unified.to/integrations/fastbill"
description: "Build FastBill integrations faster with our Unified API — Accounting data, API key, real-time sync."
date: "2026-11-02T12:21:17.863Z"
updated: "2026-11-02T12:21:17.863Z"
---
![](https://api.unified.to/docs/images/fastbill.png)

# FastBill integration

[Back to integrations](https://docs.unified.to/integrations.md)

#### Overview

Company website:

<https://www.fastbill.com>

Integration launch date:

November 2, 2026

API Categories:

[Accounting](https://docs.unified.to/accounting/overview.md)[E-Commerce](https://docs.unified.to/commerce/overview.md)[Passthrough](https://docs.unified.to/passthrough/overview.md)

API Authorization:

 Email Address / API Key

#### ACCOUNTING CONTACT

End-API object:

 customer

Unified API Methods:

[List](https://docs.unified.to/accounting/contact/List%5Fall%5Fcontacts.md)[Get](https://docs.unified.to/accounting/contact/Retrieve%5Fa%5Fcontact.md)[Create](https://docs.unified.to/accounting/contact/Create%5Fa%5Fcontact.md)[Update](https://docs.unified.to/accounting/contact/Update%5Fa%5Fcontact.md)[Remove](https://docs.unified.to/accounting/contact/Remove%5Fa%5Fcontact.md)

List options:

limitoffsetquery

Readable fields:

[billing\_address](https://docs.unified.to/accounting/contact/model.md)[company\_name](https://docs.unified.to/accounting/contact/model.md)[created\_at](https://docs.unified.to/accounting/contact/model.md)[currency](https://docs.unified.to/accounting/contact/model.md)[emails](https://docs.unified.to/accounting/contact/model.md)[first\_name](https://docs.unified.to/accounting/contact/model.md)[id](https://docs.unified.to/accounting/contact/model.md)[identification](https://docs.unified.to/accounting/contact/model.md)[is\_customer](https://docs.unified.to/accounting/contact/model.md)[is\_supplier](https://docs.unified.to/accounting/contact/model.md)[last\_name](https://docs.unified.to/accounting/contact/model.md)[name](https://docs.unified.to/accounting/contact/model.md)[payment\_methods](https://docs.unified.to/accounting/contact/model.md)[payment\_terms](https://docs.unified.to/accounting/contact/model.md)[portal\_url](https://docs.unified.to/accounting/contact/model.md)[tax\_number](https://docs.unified.to/accounting/contact/model.md)[telephones](https://docs.unified.to/accounting/contact/model.md)[updated\_at](https://docs.unified.to/accounting/contact/model.md)[website](https://docs.unified.to/accounting/contact/model.md)

Writable fields:

[billing\_address](https://docs.unified.to/accounting/contact/model.md)[company\_name](https://docs.unified.to/accounting/contact/model.md)[currency](https://docs.unified.to/accounting/contact/model.md)[emails](https://docs.unified.to/accounting/contact/model.md)[first\_name](https://docs.unified.to/accounting/contact/model.md)[identification](https://docs.unified.to/accounting/contact/model.md)[last\_name](https://docs.unified.to/accounting/contact/model.md)[name](https://docs.unified.to/accounting/contact/model.md)[tax\_number](https://docs.unified.to/accounting/contact/model.md)[telephones](https://docs.unified.to/accounting/contact/model.md)[website](https://docs.unified.to/accounting/contact/model.md)

#### ACCOUNTING INVOICE

End-API object:

 invoice

Unified API Methods:

[List](https://docs.unified.to/accounting/invoice/List%5Fall%5Finvoices.md)[Get](https://docs.unified.to/accounting/invoice/Retrieve%5Fan%5Finvoice.md)[Create](https://docs.unified.to/accounting/invoice/Create%5Fan%5Finvoice.md)[Update](https://docs.unified.to/accounting/invoice/Update%5Fan%5Finvoice.md)[Remove](https://docs.unified.to/accounting/invoice/Remove%5Fan%5Finvoice.md)

List options:

contact\_idend\_ltlimitoffsetstart\_gte

Readable fields:

[contact\_id](https://docs.unified.to/accounting/invoice/model.md)[currency](https://docs.unified.to/accounting/invoice/model.md)[discount\_amount](https://docs.unified.to/accounting/invoice/model.md)[due\_at](https://docs.unified.to/accounting/invoice/model.md)[exchange\_rate](https://docs.unified.to/accounting/invoice/model.md)[extended\_notes](https://docs.unified.to/accounting/invoice/model.md)[id](https://docs.unified.to/accounting/invoice/model.md)[invoice\_number](https://docs.unified.to/accounting/invoice/model.md)[is\_inclusive\_of\_tax](https://docs.unified.to/accounting/invoice/model.md)[lineitems](https://docs.unified.to/accounting/invoice/model.md)[notes](https://docs.unified.to/accounting/invoice/model.md)[paid\_amount](https://docs.unified.to/accounting/invoice/model.md)[paid\_at](https://docs.unified.to/accounting/invoice/model.md)[payments](https://docs.unified.to/accounting/invoice/model.md)[posted\_at](https://docs.unified.to/accounting/invoice/model.md)[project\_id](https://docs.unified.to/accounting/invoice/model.md)[reference](https://docs.unified.to/accounting/invoice/model.md)[status](https://docs.unified.to/accounting/invoice/model.md)[sub\_total\_amount](https://docs.unified.to/accounting/invoice/model.md)[tax\_amount](https://docs.unified.to/accounting/invoice/model.md)[total\_amount](https://docs.unified.to/accounting/invoice/model.md)[type](https://docs.unified.to/accounting/invoice/model.md)[updated\_at](https://docs.unified.to/accounting/invoice/model.md)[url](https://docs.unified.to/accounting/invoice/model.md)

Writable fields:

[contact\_id](https://docs.unified.to/accounting/invoice/model.md)[currency](https://docs.unified.to/accounting/invoice/model.md)[is\_inclusive\_of\_tax](https://docs.unified.to/accounting/invoice/model.md)[lineitems](https://docs.unified.to/accounting/invoice/model.md)[posted\_at](https://docs.unified.to/accounting/invoice/model.md)[project\_id](https://docs.unified.to/accounting/invoice/model.md)[reference](https://docs.unified.to/accounting/invoice/model.md)

#### ACCOUNTING QUOTE

End-API object:

 estimate

Unified API Methods:

[List](https://docs.unified.to/accounting/quote/List%5Fall%5Fquotes.md)[Get](https://docs.unified.to/accounting/quote/Retrieve%5Fa%5Fquote.md)[Create](https://docs.unified.to/accounting/quote/Create%5Fa%5Fquote.md)[Remove](https://docs.unified.to/accounting/quote/Remove%5Fa%5Fquote.md)

List options:

contact\_idend\_ltlimitoffsetstart\_gte

Readable fields:

[contact\_id](https://docs.unified.to/accounting/quote/model.md)[currency](https://docs.unified.to/accounting/quote/model.md)[currency\_rate](https://docs.unified.to/accounting/quote/model.md)[customer\_message](https://docs.unified.to/accounting/quote/model.md)[discount\_amount](https://docs.unified.to/accounting/quote/model.md)[expires\_at](https://docs.unified.to/accounting/quote/model.md)[id](https://docs.unified.to/accounting/quote/model.md)[issued\_at](https://docs.unified.to/accounting/quote/model.md)[lineitems](https://docs.unified.to/accounting/quote/model.md)[project\_id](https://docs.unified.to/accounting/quote/model.md)[quote\_number](https://docs.unified.to/accounting/quote/model.md)[status](https://docs.unified.to/accounting/quote/model.md)[sub\_total\_amount](https://docs.unified.to/accounting/quote/model.md)[tax\_amount](https://docs.unified.to/accounting/quote/model.md)[tax\_mode](https://docs.unified.to/accounting/quote/model.md)[title](https://docs.unified.to/accounting/quote/model.md)[total\_amount](https://docs.unified.to/accounting/quote/model.md)[url](https://docs.unified.to/accounting/quote/model.md)

Writable fields:

[contact\_id](https://docs.unified.to/accounting/quote/model.md)[lineitems](https://docs.unified.to/accounting/quote/model.md)[issued\_at](https://docs.unified.to/accounting/quote/model.md)[tax\_mode](https://docs.unified.to/accounting/quote/model.md)

 required fields 

#### ACCOUNTING BILL

End-API object:

 expense

Unified API Methods:

[List](https://docs.unified.to/accounting/bill/List%5Fall%5Fbills.md)[Get](https://docs.unified.to/accounting/bill/Retrieve%5Fa%5Fbill.md)

List options:

end\_ltlimitoffsetstart\_gte

Readable fields:

[bill\_number](https://docs.unified.to/accounting/bill/model.md)[currency](https://docs.unified.to/accounting/bill/model.md)[due\_at](https://docs.unified.to/accounting/bill/model.md)[exchange\_rate](https://docs.unified.to/accounting/bill/model.md)[extended\_notes](https://docs.unified.to/accounting/bill/model.md)[id](https://docs.unified.to/accounting/bill/model.md)[lineitems](https://docs.unified.to/accounting/bill/model.md)[notes](https://docs.unified.to/accounting/bill/model.md)[paid\_at](https://docs.unified.to/accounting/bill/model.md)[posted\_at](https://docs.unified.to/accounting/bill/model.md)[project\_id](https://docs.unified.to/accounting/bill/model.md)[status](https://docs.unified.to/accounting/bill/model.md)[sub\_total\_amount](https://docs.unified.to/accounting/bill/model.md)[tax\_amount](https://docs.unified.to/accounting/bill/model.md)[total\_amount](https://docs.unified.to/accounting/bill/model.md)[url](https://docs.unified.to/accounting/bill/model.md)

Writable fields:

[\-none-](https://docs.unified.to/accounting/bill/model.md)

#### ACCOUNTING SALESRECEIPT

End-API object:

 revenue

Unified API Methods:

[List](https://docs.unified.to/accounting/salesreceipt/List%5Fall%5Fsalesreceipts.md)[Get](https://docs.unified.to/accounting/salesreceipt/Retrieve%5Fa%5Fsalesreceipt.md)

List options:

contact\_idend\_ltlimitoffsetstart\_gte

Readable fields:

[billing\_address](https://docs.unified.to/accounting/salesreceipt/model.md)[contact\_id](https://docs.unified.to/accounting/salesreceipt/model.md)[currency](https://docs.unified.to/accounting/salesreceipt/model.md)[exchange\_rate](https://docs.unified.to/accounting/salesreceipt/model.md)[id](https://docs.unified.to/accounting/salesreceipt/model.md)[is\_inclusive\_of\_tax](https://docs.unified.to/accounting/salesreceipt/model.md)[lineitems](https://docs.unified.to/accounting/salesreceipt/model.md)[notes](https://docs.unified.to/accounting/salesreceipt/model.md)[posted\_at](https://docs.unified.to/accounting/salesreceipt/model.md)[project\_id](https://docs.unified.to/accounting/salesreceipt/model.md)[receipt\_number](https://docs.unified.to/accounting/salesreceipt/model.md)[reference](https://docs.unified.to/accounting/salesreceipt/model.md)[status](https://docs.unified.to/accounting/salesreceipt/model.md)[sub\_total\_amount](https://docs.unified.to/accounting/salesreceipt/model.md)[tax\_amount](https://docs.unified.to/accounting/salesreceipt/model.md)[total\_amount](https://docs.unified.to/accounting/salesreceipt/model.md)[updated\_at](https://docs.unified.to/accounting/salesreceipt/model.md)

Writable fields:

[\-none-](https://docs.unified.to/accounting/salesreceipt/model.md)

#### ACCOUNTING PROJECT

End-API object:

 project

Unified API Methods:

[List](https://docs.unified.to/accounting/project/List%5Fall%5Fprojects.md)[Get](https://docs.unified.to/accounting/project/Retrieve%5Fa%5Fproject.md)[Create](https://docs.unified.to/accounting/project/Create%5Fa%5Fproject.md)[Update](https://docs.unified.to/accounting/project/Update%5Fa%5Fproject.md)[Remove](https://docs.unified.to/accounting/project/Remove%5Fa%5Fproject.md)

List options:

contact\_idlimitoffset

Readable fields:

[code](https://docs.unified.to/accounting/project/model.md)[contact\_id](https://docs.unified.to/accounting/project/model.md)[currency](https://docs.unified.to/accounting/project/model.md)[due\_at](https://docs.unified.to/accounting/project/model.md)[id](https://docs.unified.to/accounting/project/model.md)[name](https://docs.unified.to/accounting/project/model.md)[started\_at](https://docs.unified.to/accounting/project/model.md)

Writable fields:

[contact\_id](https://docs.unified.to/accounting/project/model.md)[currency](https://docs.unified.to/accounting/project/model.md)[due\_at](https://docs.unified.to/accounting/project/model.md)[name](https://docs.unified.to/accounting/project/model.md)[started\_at](https://docs.unified.to/accounting/project/model.md)

#### COMMERCE ITEM

End-API object:

 article

Unified API Methods:

[List](https://docs.unified.to/commerce/item/List%5Fall%5Fitems.md)[Get](https://docs.unified.to/commerce/item/Retrieve%5Fan%5Fitem.md)[Create](https://docs.unified.to/commerce/item/Create%5Fan%5Fitem.md)[Update](https://docs.unified.to/commerce/item/Update%5Fan%5Fitem.md)[Remove](https://docs.unified.to/commerce/item/Remove%5Fan%5Fitem.md)

List options:

limitoffset

Readable fields:

[description](https://docs.unified.to/commerce/item/model.md)[global\_code](https://docs.unified.to/commerce/item/model.md)[id](https://docs.unified.to/commerce/item/model.md)[name](https://docs.unified.to/commerce/item/model.md)[prices](https://docs.unified.to/commerce/item/model.md)[tags](https://docs.unified.to/commerce/item/model.md)[type](https://docs.unified.to/commerce/item/model.md)

Writable fields:

[description](https://docs.unified.to/commerce/item/model.md)[global\_code](https://docs.unified.to/commerce/item/model.md)[name](https://docs.unified.to/commerce/item/model.md)[prices](https://docs.unified.to/commerce/item/model.md)[tags](https://docs.unified.to/commerce/item/model.md)[type](https://docs.unified.to/commerce/item/model.md)

#### PASSTHROUGH

Unified API Methods:

[POST](https://docs.unified.to/passthrough/overview.md)[GET](https://docs.unified.to/passthrough/overview.md)[PUT](https://docs.unified.to/passthrough/overview.md)[DELETE](https://docs.unified.to/passthrough/overview.md)

List options:

\-none-

Readable fields:

[\-none-](https://docs.unified.to/passthrough/undefined/model.md)

Writable fields:

[\-none-](https://docs.unified.to/passthrough/undefined/model.md)