Accounting automation

Overview

The Automation page in your dashboard, helps you create and manage automation. You can create both mappings and custom rules so that your transaction information carries over to your ERP at the time of export.

Automating accounting categorization with mappings and custom rules and setting automated workflows for your transactions can dramatically reduce the time you spend coding transactions each month.

Mappings help you pair Brex fields with ERP or HRIS fields to auto-populate important fields such as GL account, department, or class. Custom rules allow you to create logical relationships between multiple fields.

Accessing Automation

You can find the Automations page by signing into your dashboard and going to Accounting > Manage automation.

Mappings

Mappings can automate your accounting categorization and reduce your time spent manually coding. You can map your expense fields to the accounting fields in your ERP or even to custom fields you have in Brex. For example, if you map Brex categories to GL accounts, we’ll automatically map new expenses to a designated GL account, depending on their Brex category.

Category mappings match each of Brex’s default 48 categories to a GL account in your accounting software. Merchant mapping allows you to automatically set a GL account based on the transaction merchant and will override category mapping.

Create mappings

Account admins, card admins, and bookkeepers can set mappings by following these steps: Step 1: Go to Accounting > Manage automations > Mappings. Step 2: Click Create mapping. Step 3: From the dropdown on the left, choose the value that corresponds to the field on the expense (e.g., Brex location). From the dropdown on the right, select the value that will automatically be filled in based on that expense (e.g., Location).

Mapping lists all existing mappings. You can click on any of the line items to view or edit them.

Mappings will apply to all new transactions in your Prepare tab. If there's a conflict, any custom rules you've set up will take priority over these mappings.

Custom rules

All plans

You can enable custom rules in Company settings > Plan > Custom accounting rules. Enabling custom rules overrides your ability to change expense fields, such as Department and Location.

Custom rules automatically categorize transactions that share similar expense fields, reducing the need for manual entries when closing the books. These rules let you establish logical relationships between fields that go beyond basic mappings.

Here’s an example of a custom rule that filters transactions with two expense fields in order to auto-code a GL account field: Brex category: Advertising & marketing + Merchant: Meta > GL account: 6010 Advertising Custom rules can be created by combining any Brex transaction fields, including these:

• Amount (greater than, lesser than, or equal to)
• Approved (yes or no)
• Card (specific card that made the purchase)
• Category
• Cost center
• Department
• Location
• Memo (has a memo or not)
• Merchant
• Receipt (has a receipt or not)
• Spend limit
• User
• Any custom fields you’ve created (including ERP fields such as location, subsidiary, and vendor)

Create custom rules

Account, card admins, and any other users with the specific product capability can create custom rules by following these steps: Step 1: Go to Accounting > Manage automations > Custom rules. Step 2: Click Create custom rule. Step 3: Fill out the two sections of the custom rule detail pane.

• For transactions that contain: Use these fields to filter the transactions you want to apply the rule to.
• Categorize these fields: Set the accounting field values you want to auto-code.

Step 4: Click Create and apply rule. Custom rules will apply to all transactions that you haven’t yet marked as prepared or exported.

Other ways to create custom rules

Early access New for Summer Essentials

In addition to the Automation page, you can also create custom rules directly in the spend limit and p-card setup flows. When creating or editing a limit or p-card, you'll see the option to define how expenses tied to that spend provision should be categorized automatically. This lets you apply accounting logic at the point of spend, helping reduce the need for manual preparation later on.

All custom rules created—whether in the Automation page, spend limit flow, or p-card setup—will appear in the Custom rules section of the Automation Library. There, you can view, edit, or delete any existing rules to keep your accounting automations organized in one central place.

Automation preview

When you’re creating a new rule, you can use rule automation prior to implementing it to see which transactions the rule would affect. To do this, click Preview in the creation process on either Automation suggestions or on the Manage Automation page.

View or edit custom rules

Step 1: Go to Accounting > Manage automations > Custom rules. Step 2: Click the specific rule to open the details window. Step 3: In the details window, make your desired changes to the custom rule. The date on the top right of the details pane tells you when the rule was last updated. Step 4: Click Save and apply rule.

Delete custom rules

Step 1: Go to Accounting > Manage automations > Custom rules.

Step 2: Click the specific rule to open the details pane.

Step 3: Click the three dots to the bottom left and click Delete rule.

Solving rule conflicts

Rules are assigned different priority levels, which decide which rule is applied. Conflicts can occur when two rules of the same priority contradict each other.

In the event of a conflict between two custom rules, we’ll ask you to choose which rule to apply. To find transactions with conflicting rules, click Conflicting rules in the Accounting flag filter. To solve the conflict on a case-by-case basis, click on the transaction and choose the rule that takes precedence in the Accounting section. The transaction will be considered Manually recategorized.

Automation suggestions

New for Summer

Brex Assistant will suggest values, mappings or custom rules for you to consider creating based on semantic similarity (e.g. names are similar) or your past transaction categorization. For example, if you frequently assign certain GL accounts to transactions that have the same Brex category, we may suggest a mapping that automates codification. You can find suggestions in multiple places in the accounting dashboard.

In-table suggestions

We’ll suggest values, mappings, and custom rules as you categorize your transactions.

To accept the suggestion, simply click on one of the values highlighted under Suggested by Assistant.

To create a new rule, click Create rule when choosing a value for a given field. In the details window, review the rule and either accept or reject it. You can also revise the suggested mapping before accepting it.

Automation home

You can find all suggestions in Accounting > Manage automations.

The details window will show you all the suggestions available for you to review. You can review the custom rule and either accept, reject or revise it before accepting it. You can also click View all to see all of Brex Assistants' suggestions, where you can filter and bulk accept multiple suggestions at the same time.

Automating your accounting workflows

Early access New for Summer

Brex makes it easier than ever to automate how you prepare and export transactions to your ERP. With Automated Workflows, you can define custom logic that mirrors your internal accounting policies—no more manual steps or duplicate work.

Save time by eliminating repetitive manual steps in your accounting workflow, reduce errors by applying consistent rules across spend categories, and gain clarity by seeing exactly what’s automated and why, directly from the transaction view. Automated Workflows also help you stay compliant by structuring rules to mirror your internal accounting policies, including travel, bill pay, and reimbursement scenarios.

You can configure these workflows directly in the Manage Automation > Workflows tab.

What you can automate

You can automate both:

• Preparation: Automatically mark as prepared transactions that fulfill certain conditions, such as passing policy, having certain accounting fields filled, or being below a certain threshold.
• Export: Automatically send transactions to your ERP once they're ready—no clicks required.

You can set up rules to perform one or both actions independently. For example, you might auto-prepare all team offsite expenses but still review them manually before exporting.

How to get started

Step 1: Go to Manage Automation > Workflows in your Brex dashboard.

Step 2: Select one of the existing Workflows and click on the + sign to add conditions.

Step 3: Set up your logic in the Workflow conditions screen:

• Use IF conditions to determine which fields or conditions are needed to automatically prepare or export transactions.

You can add multiple conditions and actions within a single rule, making it easier to reflect your internal policy structure.

Step 4: Click on Apply workflow to save and execute the rules.

Note: In the automatically export from review workflow, you can also define the cadence (hourly, daily, weekly, or monthly) with which Brex will post your transactions to the ERP.

Tracking the effect of automation

Once your rules are live, transactions will be automatically marked as Prepared or Exported when conditions are met.

You can track these in the Accounting > Prepare and Accounting > Review tabs.

Here’s a transaction automatically prepared using a workflow:

And here’s one that was automatically exported:

Hover over these labels to see which rule was applied. This gives your team full visibility into automation behavior—no surprises.