PSA posting and proration date errors

This article explains common PSA posting errors that happen when Sync 365 updates Microsoft 365 licence quantities, Azure billing, or custom billing items into your PSA agreement or contract.

These errors are usually caused by agreement dates, contract billing periods, proration settings, inactive PSA products, missing permissions, or an invalid start date.

When this article applies

Use this article when:

• A licence or billing item is not updating in the PSA.
• Sync 365 shows an error in the sync log.
• The PSA rejects an addition or contract charge.
• A quantity change does not appear on the agreement or contract.
• You see an error about an effective date, start date, billing period, or prorate setting.

Common error: addition object is invalid

This error usually means the PSA rejected one of the fields Sync 365 tried to send.

Common causes include:

• The effective date is before the agreement billing start date.
• The agreement period has already been invoiced.
• Proration is disabled and the selected start date is inside an already billed period.
• The PSA product or service is inactive or no longer exists.
• The agreement or contract is not in a valid state for updates.

Error: effective date cannot be less than the agreement billing start date

This happens when Sync 365 tries to create or update an item using a start date earlier than the PSA agreement billing start date.

How to fix it

1. Open the customer company in Sync 365.
2. Find the affected licence or billing item.
3. Check whether an override start date is set.
4. Change the override start date so it is on or after the agreement billing start date.
5. Save the mapping and allow the sync to run again.

Error: period has already been invoiced

Some PSAs will not allow new products or additions to be added into a billing period that has already been invoiced, especially when proration is disabled.

The error may say something similar to:

Since this period has already been invoiced there will not be an invoice generated for additional products for this period. Please prorate the agreement or update the start date to on or after the next invoice date.

How to fix it

1. Check the agreement or contract next invoice date in the PSA.
2. Update the Sync 365 override start date to the next invoice date or later.
3. If appropriate for your billing process, enable proration in the PSA agreement or contract.
4. Save the mapping and allow Sync 365 to retry the update.

If you do not want prorated line items, set the start date to the next invoice period rather than enabling proration.

ConnectWise proration behaviour

ConnectWise agreement behaviour depends heavily on the agreement billing setup and whether proration is enabled.

• If proration is enabled, ConnectWise may create prorated line items for mid-period changes.
• If proration is disabled, ConnectWise may reject additions that start in an already invoiced period.
• If the effective date is before the agreement start date, ConnectWise may reject the update.

For cleaner invoices, some MSPs prefer to avoid prorated additions and use start dates aligned to the next billing period. This is a billing process decision and should match how you invoice customers.

Autotask proration behaviour

Autotask can apply prorated service changes based on the contract and service effective dates.

If you disable proration for an Autotask company in Sync 365, quantity or service changes are generally aligned to the contract billing period instead of creating prorated line items.

Be careful when changing proration settings mid-period, because it can affect how Autotask calculates the next invoice.

PSA product or service errors

If a PSA product, service, SKU, or catalogue item linked to a billing profile has been deleted or made inactive, Sync 365 may not be able to post the update.

How to fix it

1. Open the billing profile in Sync 365.
2. Check the linked PSA product or service.
3. Confirm the item still exists and is active in the PSA.
4. Either reactivate the PSA item or update the billing profile to use a valid active item.
5. Save and allow the sync to retry.

PSA permission errors

If the PSA API user does not have enough permission to access agreements, contracts, products, services, or customers, the PSA may reject the request.

Check that the API user has access to:

• Companies or accounts
• Agreements or contracts
• Products or services
• Agreement additions or contract services
• Relevant agreement or contract types

For ConnectWise, pay special attention to agreement type restrictions. If access is limited by agreement type, make sure both parent and child agreement types are included where relevant.

What to check before contacting support

1. Check the Sync 365 error log for the exact error message.
2. Confirm the PSA agreement or contract is active.
3. Confirm the PSA product or service is active.
4. Check the agreement or contract billing start date.
5. Check the next invoice date.
6. Check whether proration is enabled or disabled.
7. Check whether Sync 365 has an override start date set.
8. Confirm the PSA API user has the required permissions.

Best practice

• Use override start dates during initial migration to align with your next billing period.
• Do not use a start date before the PSA agreement or contract start date.
• If proration is disabled, avoid posting new additions into already invoiced periods.
• Keep PSA products and services active if they are linked to Sync 365 billing profiles.
• Review PSA API permissions after changing PSA roles, agreement types, or contract structure.
• Clean up old manual or legacy billing additions when moving to Sync 365 automation.

When to contact support

Contact support if:

• The error remains after correcting dates and products.
• You are unsure which start date should be used.
• The PSA error message is unclear.
• The item appears to sync successfully but does not appear in the PSA.
• The PSA quantity is different from the Sync 365 quantity after a sync.

When contacting support, include the company name, PSA agreement or contract, licence or billing item name, billing profile, exact error message, and screenshots of the Sync 365 mapping and PSA agreement/contract dates.

Related articles

• Addition object is invalid
• Catalog Item # not found
• Permission Error – You do not have security permission to perform this action
• How Prorate works - Connectwise
• Autotask Feature: Disable Prorate