Wales Pupil Level Annual School Census (PLASC) - General Guide and Overview

The Pupil Level Annual School Census (PLASC) is a mandatory electronic data collection for all maintained nursery, primary, middle, secondary, and special schools in Wales. The data submitted is used by the Welsh Government and Local Authorities for funding distribution, policy research, and ensuring accurate pupil records.

This guide provides an overview of the return requirements and how to generate your return in Arbor.

PLASC Series

This is the first guide in our series on completing the Wales PLASC. You can access the other guides in the series here:

• Wales PLASC - General Guide and Overview (This guide)
• Wales PLASC - The Classes Page 
• Wales PLASC - Meals and School Characteristics
• Wales PLASC - Pupil Counts
• Wales PLASC - Teachers and Support Staff
• Wales PLASC - Teaching of Welsh 

Permissions

• To access and manage the census, you must have the Data Returns: Administer permission.

If you do not have this permission, ask your office staff or administrator to add it to your profile for you.

Key Dates and Changes

Important Dates

• Census Day: Tuesday 20 January 2026
• Submission Deadline (to Welsh Government): Friday 6 March 2026

Key Changes 2026: ALN Transition

The most significant change for the 2026 census is the transition from Special Educational Needs (SEN) to Additional Learning Needs (ALN).

• SEN Removal: All SEN data items have been removed.
• ALN Implementation: These have been replaced by ALN data items following the end of the legacy SEN system in August 2025.

Key Functionality

The Data Returns feature provides the following key functionality for completing the PLASC data return:

• Census Return Overview: This feature displays the current status of all census returns, links to each census run, and enables the generation of a new census and the download of the latest successful return and summary files.
• Census Generation Overview: This feature displays the status of an individual census return, allowing for the download of its XML and Summary files, as well as a list of Errors and queries specific to that generation.
• Dry Run Generation: This is key for preparatory work, allowing you to generate census output before the census officially opens. This helps schools identify errors and queries early, becoming familiar with the process.
• Census Generation: Becomes available after the census has opened and is used for live submission.
• Census XML Download: The generated Census XML file can be downloaded directly from Arbor, ready for submission or inspection.
• Errors and Queries lists: This feature displays the list of errors and queries generated by the Welsh Government-supplied validation rules, enabling schools to correct any data problems before re-running the census.
• Welsh Govt. Summary Download: Downloads a PDF summary of the data. Schools typically use this to verify key numbers and must physically sign a copy of this document.
• Completer Hours Data Entry: Provides a simple feature to input information about the total number of hours staff spent completing the census for each role. This data is automatically totalled and included in the census output.
• Data Return Homepage Banner: Arbor automatically shows a homepage banner reminding the school about an outstanding data return. Marking a data return as submitted (by adding a submitted date) will hide the banner.
• On-The-Day Data Areas: these pages allow you to manage, check and enter on-the-day snapshot data that is required for the PLASC return. Examples include class information and pupil counts.

Navigation

From the Data Returns page

To access the PLASC return in Arbor:

• Go to School > Data > Export > Data Returns.
• Select PLASC from the list of returns to access the PLASC Overview page
   

The banner on the Homepage

Once the Pupil Level Annual School Census date (also known simply as Census Day) has passed, staff will see a warning banner on their Homepage as a reminder to submit the Return. The banner includes a useful Census Help button that links to our Help Centre for further guidance on completing the census.

The banner shows on homepages from the opening date of the return until the return is marked as Submitted or the Return closing date has passed. 

You can find the return and closing dates for a specific return by going to School > Data > Export > Data Returns, clicking on the census/return you are interested in and referring to the Return Details section at the top of the page.

Once you have submitted your return to the Welsh Government, you have the option to add a submitted date and time to your Return Details, which marks your Return as submitted in Arbor and removes the warning banner from your homepage. To add a submitted date:

• Head to your return's Overview Page
• Click on the Submitted datetime in the Return Details section
• Add a date on the slide-over
• Press Save 

Submitted datetime only shows if you have a return listed in the Active tab. If you have only generated Dry Runs so far, you do not see this field. Adding a Submitted Date will not prevent you from generating a new version of the Return.

Generating a Return

Dry Runs vs. Live Generation

• Dry Run Generation: Allows you to generate the census before it formally opens, enabling you to identify and correct errors early. Dry runs are not intended to be submitted. Once the census date has passed, a Live Census needs to be generated to capture on-the-day snapshot data.
• Live Census Generation: Becomes available after the census opening date and is identical to the dry run, but also contains snapshot data.

Generating a Census

• Head to your PLASC Return Overview page via School > Data > Export > Data Returns or the banner on the homepage
• On the left-hand side, click the Generate (Dry Run) button
   

• The system will then create the census XML file and a PDF Summary. You'll receive a notification (the Bell icon on the left-hand side of Arbor) once the generation is complete.
   

Checking and Submitting the Return

Census XML Download

The download button on the right of the overview will download the XML census output to your computer ready to submit to your LA or Welsh Government, or if you wish to browse the content yourself. Please take care with these files as they can contain a lot of personal information.

Errors and Queries

To view and amend errors/queries, you need to have generated a Dry Run Census or Census.

Top Tip: We recommend that you work through your errors and queries in batches and then regenerate after resolving a few to minimise time spent waiting for regeneration. Remember, the errors will only disappear after you’ve regenerated your census!

Resolve your Arbor Validation errors first.

This will usually clear one or more Welsh Government Validation errors at the same time.

1. Click on an Arbor Validation error, a slide-over will open

2. Enter the correct information.

3. Click the green button to save your changes

Once you have resolved as many Arbor errors as you can, start resolving your Welsh Govt. Validation errors.

In the generation overview, you will be shown the Errors and Queries generated by the Welsh Government’s validation rules for the census generation, for many errors, you can click directly through to the record with the problem.

Top Tip: Always regenerate your Census before leaving the Census pages to ensure that any work you have done is saved and recorded.

After making your corrections/adjustments, select Generate to create a new version of the census so the data can be re-checked.

Welsh Government Summary Download

Download the census summary (.pdf) containing tables summarising the data contained within the XML return. This contains the sign-off form and shows the date + time matching the corresponding XML return.

Census Completer Hours

The census requires a list of the roles of the staff members who have spent time completing the census and the time spent (in whole hours). This can be recorded here:

• School > Data > Export > Data Returns
• Select PLASC
• Select Completer Hours on the left

To add a new entry, select the (+)Add link and enter the number of hours and the role of the staff member.

You may add multiple entries for any role(s), or edit (or delete) an entry by selecting it from the Census Completer Log table. Note: The hours will be automatically summed per role and included in the next census generation.

Data Included in the Return

• School Identifiers & Characteristics:

  • Basic details: LEA number, School Phase, and UKPRN.

  • Census Day Attendance: Headcounts for Full-time and Part-time pupils present for at least one session on census day.

  • Attendance Patterns: Specific counts for Morning, Afternoon, and "Other" attendance for part-time pupils.

  • School Meals & Milk: Counts for free/paid meals taken on census day, plus free/paid milk.

  • Free Breakfast Initiative: Pupils taking free breakfasts on census day and during the previous typical school week.

• Governance & Staffing:

  • Governing Body: Male/Female counts, Welsh-speaking governors, vacancies, and Federated Governing Body IDs.

  • Workforce Modules: Despite SWAC, PLASC still requires headcounts and hours for Teachers, Support Staff, and "Teaching of Welsh" staff.

• Classes as Taught:

  • Details of all classes running during the third period on census day.

  • Class Size Exceptions: For Primary/Middle schools, reasons for classes over 30:1 pupil: teacher ratio

  • Class Details: Names, year groups, Welsh teaching levels, and staff-to-pupil ratios.

• Individual Pupil Data:

  • Identifiers: UPN, ULN (for pupils 14+), and former UPNs.

  • Characteristics: Ethnicity, National Identity, and FSM Transitional Protection status.

  • ALN Module: The specific ALN Support Plan type and the pupil's primary and secondary needs.

  • Welsh Language: Fluency levels, Welsh medium education indicator, and use of Welsh at home.

  • Exclusions: All Fixed and Permanent exclusions that occurred during the 2024/2025 academic year.