Upload files

Everything in this guide happens on the Files tab of Train. Open Train from the menu on the left and it opens on Files, so there is nothing else to click. You need Train access to see it. Admins always have it, and an admin can give it to anyone else from Edit users and roles.

The other four tabs add knowledge in other ways. Integrations syncs folders from Google Drive, OneDrive, SharePoint, Dropbox and Microsoft Teams, Websites reads pages from a web address, Text / Audio takes notes you type or record, and Skills holds the instructions, templates and layouts Centrus follows when it builds a spreadsheet, PDF, slide deck or report for you in chat (see Skills). Files is the place for documents saved on your own computer or phone. To keep a shared drive in step with Train instead, see Sync Google Drive or Train from a website.

Train accepts ten file types. Each file is turned into text that Centrus can search, so what matters is the words inside the file rather than how it looks.

• PDFs and Word documents are read for their text, headings and tables. A scanned PDF that is only a picture of each page has no text to read, so run it through text recognition (OCR) first, or upload the original document instead.
• Spreadsheets are converted into tables before Centrus reads them, one table for each worksheet, so keep a heading row at the top of every sheet. The file in Train keeps its original name and format.
• Audio is transcribed, and Centrus answers from the transcript. The transcription service takes files of up to 25 MB, so split a long recording into shorter files.
• Text, Markdown and HTML files are read as they are.

Video, images and PowerPoint files are not accepted, and neither are older Word files saved as .doc, so save those as .docx first. If you would rather paste notes in than upload a file, use Text / Audio.

The file extension needs to be in lower case. A file called Report.PDF is marked as failed, but the same file renamed to Report.pdf uploads normally.

1. 1Open Train. It opens on the Files tab.
2. 2Drag one or more files from your desktop or a folder onto the dashed upload box. You can drop as many as you like at once.
3. 3Alternatively, click anywhere in the box to open your file browser, then choose the files you want.
4. 4Watch the Uploading Files panel in the bottom right corner until every file shows a green tick.

Files are uploaded and then read one by one, so a large PDF or a long recording takes longer than a short document. You can carry on working elsewhere in Centrus while that happens, but keep the browser tab open until the panel shows every file as finished.

On a screen narrower than 700 pixels, which covers most phones, the upload box is replaced by a single Upload File button. Tap it to choose files saved on your phone. Everything else on the Files tab works the same way, with each file shown as a card rather than a row.

09:41

Centrus

Train

Add data sources to train Centrus

Upload FileChoose files saved on your phone

FoldersCreate

Zone 3 panel manual.pdf

TechnicalSecond tag

4.2MB06/10/2026 09:14

Gas Safe RAMS template.docx

SOPsSecond tag

186kB06/10/2026 09:16

Rate card 2026.xlsx

PricingSecond tag

92.4kB03/10/2026 16:40

As soon as you drop files, an Uploading Files panel opens in the bottom right corner of the screen. The newest file is at the top, and each line shows the file name and size with one of three marks:

• a spinning circle while the file is uploading and being read
• a green tick when the file is in Train and ready to tag
• a red cross when the file could not be added.

Once nothing is still processing, a small close button appears in the corner of the panel so you can dismiss it.

A red cross usually has one of three causes: the file type is not on the list above, the extension is in capitals, or your organisation has run out of storage. When storage is the cause, a message at the top of the screen says that some files could not be uploaded due to storage limits, and any files that fitted are still added. A file of an unsupported type can show a message about file size limits instead, even though its size is not the problem.

A new upload has no tag, and this is the step that matters most. Centrus answers from files that carry the tags a chat is allowed to search, so an untagged file sits in Train without ever being used in an answer. Until it has a tag, it is also hidden from everyone except admins and the person who uploaded it.

1. 1Find the file in the list and click Primary tag on its row.
2. 2Choose a tag from the list. Start typing to narrow the list down, or type a new name and choose Create to make a new tag there and then.
3. 3To add another tag, click Second tag, which appears once the first is set, and then Third tag if you need it.

A file can carry up to three tags, and each tag decides who can find the file in chat. Click a tag on a row to replace it with another, or click the small cross beside it to remove it. Parent tags never appear in the list, because they group other tags rather than hold files.

Each tag after the first counts the file's size against your storage again, so a 10 MB file with three tags uses 30 MB. Add a second or third tag only when different groups of people need the same file.

Which tags exist, and who can use each one, is set up in Settings. See Control who sees what with tags.

After a large upload it is quicker to work on files together. Tick the checkbox on each row, or click Select All above the list, and an Actions button appears with a count of the files you have selected.

• Apply Tag sets the tag you choose as the primary tag on every selected file, replacing any primary tag they already had. Create new tag, at the bottom of the list, makes a new tag first.
• Add to folder puts the selected files into one of your folders.
• Delete removes the selected files from Train straight away. There is no confirmation step for several files, so check the selection before you click it.

Select All only picks up the files currently loaded on the page. The list loads 25 files at a time as you scroll, so scroll to the end first if you want to include more.

Folders help you find related files quickly, such as everything for one site or one contract. They are personal, so only you can see the folders you create, and they have no effect on who can use a file in chat. That is what tags are for.

The Folders card sits under the upload box and starts collapsed. Click its header to open it.

Folders

Create1

Manual Folders

Riverside House8

2

Fire panels12

New starters5

Cloud Folders

3 cloud folders•255 documents

SharePoint214

Technical / Fire panels1762 hours ago

Contracts / Riverside382 hours ago

Google Drive41

3

Clear folder filter

4

Documents in folder (8)

Select AllSortFilterSearch documents...

Riverside House SLA.pdf

1.1MB01/10/2026 11:02SPSarah Price

ContractsTechnicalThird tag

1. 1Create makes a new folder.
2. 2Click a folder to show only its files. The pencil renames or recolours it, and the bin deletes it.
3. 3Cloud Folders lists the folders synced from Google Drive, OneDrive, SharePoint and Dropbox. Click one to see its files.
4. 4Clear folder filter takes you back to every file.

While a folder is selected, the list heading changes to Documents in folder with a count, so it is always clear that you are looking at part of Train rather than all of it. Deleting a folder never deletes the files in it. Train asks you to confirm, and the files stay in the main list.

1. 1Open the Folders card and click Create.
2. 2Type a name of up to 30 characters.
3. 3Pick one of the eight colours. The folder icon beside the name changes to match, which makes folders easy to tell apart.
4. 4Click Create Folder.

To fill the folder, select files in the list, open Actions, choose Add to folder and pick the folder. A file can sit in more than one folder, and adding it to a folder does not move it out of the main list.

The list shows the files you uploaded alongside the ones synced from your drives. A small logo beside the file icon shows where a synced file came from. Three controls above the list help you narrow it down, and they work together.

• Sort orders the list by name, from A to Z or Z to A, by file size, largest or smallest first, or by upload date, newest or oldest first.
• Filter narrows the list by Document Type (PDF, Word, Excel, text, generic or audio), by Tag, or by Source, to show only files synced from Google Drive, OneDrive, Dropbox, SharePoint, Microsoft Teams, WhatsApp or a knowledge email address.
• Search looks at file names rather than what is inside the files, so search for words you know are in the name.

Choose Filter, then Tag, then No Tag to find every file that Centrus cannot use yet. It is worth doing after any large upload.

To rename a file, double-click its name in the list, type the new name, and press Enter or click away to save. Press Escape to cancel. You do not need to type the extension, because Train keeps the original one, so renaming Riverside House SLA.pdf to Riverside House SLA 2026 saves it as Riverside House SLA 2026.pdf. A clear name makes the file easier to search for and easier to recognise when Centrus shows it as a source.

To delete a single file, click the bin at the end of its row and confirm with Delete. A deleted file is removed from Train and from every tag it carried, so Centrus stops using it straight away. Deleting cannot be undone, so keep your own copy of anything you may need again.

Admins see every file in Train. Everyone else with Train access sees two kinds of file: files that carry at least one tag they have been given, and untagged files they uploaded themselves. On a file with several tags, they only see the tags they have access to.

John Martin

Admin

Sees every file

• Zone 3 panel manual.pdfTechnical
• Riverside House SLA.pdfContractsTechnical
• Rate card 2026.xlsxPricing
• Gas Safe RAMS template.docxSOPs
• Site induction call.mp3No tag
• Van stock checklist.docxNo tag

DH

Dylan Hughes

Engineer, with Train access

Tags: Technical, SOPs

• Zone 3 panel manual.pdfTechnical
• Riverside House SLA.pdfTechnical
• Gas Safe RAMS template.docxSOPs
• Boiler fault codes.txtNo tag
• Rate card 2026.xlsxNot shown
• Van stock checklist.docx (no tag)Not shown

This is another reason to tag files promptly. Until a file has a tag, the rest of the team cannot see it in Train or get answers from it in chat. When someone who is not an admin tags a file, the list only offers the tags they have been given.

Every document in Train counts towards your organisation's storage limit, whether you uploaded it here, synced it from a drive or added it from a website. A file counts once at its original size, plus once more for each extra tag. The Small Team plan includes 1 GB and the Large Team plan includes 10 GB.

Anyone with Train access can see how much is used on the Sources bar at the foot of the Integrations and Text / Audio tabs, and admins also see it under Settings, then Billing, on the Current Plan card. The bar turns red at 90 per cent. When an upload would take you over the limit, Train skips the files that do not fit and tells you how many were left out. To make room, delete files you no longer need or remove extra tags you can do without. If you need more space, extra storage is available as an add-on. See Add-ons.