Small and medium business | Business Central, N...

Purchase Workflow to user and approved and then need to changing VAT without doing another approval

(9) Share

Report

Posted on by Raja

156

Dear Members,

I need a requirement. At first i create a workflow for Purchase Order and assigned to the user. User can create purchase order without VAT then receive the items only before receiving they send the approval request and get approved and the user only receive the item. Now before invoicing the user need to add VAT for this item without send another approval request. I tried but i can't find the solution the error occured if i add VAT like "workflow rectricted to change the line, get approval and release then change the line". I want to remove the process once i get approved i need to change somethings on line. kindly please share your solution as soon as possible.

Thanks in advance,
Raja.

Categories:

Dynamics 365 Business Central

I have the same question (0)

All responses (8)

Answers (0)

Sort by

Suggested answer

DAnny3211 11,421 Super User 2026 Season 1 on at

Like (3)

Report
Copy link

Link copied!
Hi Raja,

This is a common scenario where users need to make minor changes (like adding VAT) after a Purchase Order has already been approved. By default, Business Central’s workflow enforces restrictions on modifying lines post-approval to maintain audit integrity.

Here are a few options to consider:

Customize the Workflow Conditions:

You can modify the workflow to exclude VAT changes from triggering re-approval.

This requires customizing the workflow event conditions or using a custom codeunit to allow specific field changes post-approval.

Use a Custom Field or Flag:

Instead of modifying the VAT directly, consider adding a custom field or flag that indicates VAT needs to be added, and handle it via a separate process or approval bypass.

Create a Post-Approval Exception Rule:

You can create a custom extension that allows changes to specific fields (like VAT) after approval, while keeping other restrictions intact.

Split the Workflow:

Consider splitting the workflow into two stages:

Stage 1: Approval for item receipt.

Stage 2: Post-receipt adjustments (e.g., VAT) with limited or no approval.

If you're comfortable with AL development, I can help you design a small extension to bypass VAT-related changes after approval.

Please verify if this response was helpful.

Best regards!

Was this reply helpful? Yes No
Suggested answer

Sumit Singh 11,795 Super User 2026 Season 1 on at

Like (3)

Report
Copy link

Link copied!
Issue:-
Business Central’s workflow approval system is tightly integrated with document status and field-level change tracking. Once a document is approved and released, any modification to key fields (like VAT, quantity, amount, etc.) on lines invalidates the approval, triggering the workflow again.
This is by design to ensure compliance and audit integrity.
Solution Strategy
To allow VAT changes after approval but before posting invoice, you can follow below approaches in Sandbox environment:
Use a Custom Field for VAT Entry
Instead of modifying the standard VAT field directly:

Add a custom field (e.g., Temp VAT Group) on the Purchase Line.

Allow users to update this field post-approval.

During invoicing, use a customization or extension to map this field to the actual VAT field before posting.

This avoids triggering workflow restrictions.
Mark the Answer as Verified if this is Helpful.

1 people found this reply helpful.

Was this reply helpful? Yes No
Suggested answer

Andrés Arias 5,165 Super User 2026 Season 1 on at

Like (4)

Report
Copy link

Link copied!

Hello,

In the standard version of Business Central, it would not be possible to implement this requirement.

At the development level, an exception could be added to send the approval flow when the user makes a tax change.

I hope this helps.

Regards,

Andrés

Was this reply helpful? Yes No
EO-15071029-0 185 on at

Like (3)

Report
Copy link

Link copied!

Hi Raja, may be it's better to change business process? Send Purchase Invoice to approval.

Was this reply helpful? Yes No
Suggested answer

YUN ZHU 101,126 Super User 2026 Season 1 on at

Like (2)

Report
Copy link

Link copied!

I think customization might be a little simpler, for example, to prevent errors from being triggered when modifying a line in an approved document.

Alternatively, you can refer to the opinion of EO-15071029-0 and use another document to add VAT, such as Purchase Invoice.

Hope this helps as well.

Thanks.

ZHU

Was this reply helpful? Yes No
Sohail Ahmed 11,175 Super User 2026 Season 1 on at

Like (2)

Report
Copy link

Link copied!

In standard Business Central, once a document is approved and released, you can’t change key fields like VAT, amounts, or dimensions — because these are controlled by the workflow approval rules. This is by design, to ensure that financial impact fields aren’t changed after approval.

If you want users to be able to add/change VAT after approval without triggering workflow again, that would require customization of the workflow event handling (basically excluding VAT field changes from re-approval conditions).

👉 Best way forward: discuss with your Microsoft Partner to adjust the workflow logic so VAT changes don’t force a new approval.

Was this reply helpful? Yes No
Suggested answer

Khushbu Rajvi. 22,433 Super User 2026 Season 1 on at

Like (3)

Report
Copy link

Link copied!

Adding it for more details: https://learn.microsoft.com/en-us/dynamics365/business-central/walkthrough-setting-up-and-using-a-purchase-approval-workflow

Was this reply helpful? Yes No
Suggested answer

Jeffrey Bulanadi 9,121 Super User 2026 Season 1 on at

Like (1)

Report
Copy link

Link copied!
Hi Raja,

BC’s approval workflows are tightly bound to document status and field-level change tracking. Once a Purchase Order is approved and released, any modification to key fields like VAT, will trigger a restriction unless the workflow is designed to accommodate post-approval edits.

Here’s what’s happening and how you can work around it:

By default, BC locks down changes to approved documents to preserve audit integrity. This includes VAT fields, which are considered financially sensitive.

When you attempt to modify VAT after approval, the system interprets it as a structural change and expects a new approval cycle.

To resolve this, you have two options:

Change the Business Process

Instead of modifying the Purchase Order, allow users to add VAT during the Purchase Invoice stage.

This keeps the PO approval intact and shifts tax logic to the invoice, which is more flexible and doesn’t require reapproval.

Customize the Workflow Logic

You can modify the workflow event conditions to exclude VAT fields from triggering a new approval.

This requires AL development to adjust the WorkflowEventHandling codeunit and suppress reapproval when only VAT is changed.

Use Power Automate for Conditional Logic

If you prefer a low-code route, Power Automate can be configured to bypass reapproval for specific field changes.

This gives you more granular control over what triggers a workflow and what doesn’t.

Helpful Reference
Set up and use a purchase approval workflow – Microsoft Learn
How To Setup Approval Workflows In BC – BC Geek
Workflows in Dynamics 365 BC – Microsoft Learn

If you find this helpful, feel free to mark this as the suggested or verified answer.

Cheers
Jeffrey

1 people found this reply helpful.

Was this reply helpful? Yes No