If you've ever searched for "Business Central schema" hoping to find a clean, browseable reference of every table and field in BC, you've probably been disappointed. There's no single built-in schema viewer in Business Central. Microsoft's documentation covers individual tables across hundreds of separate pages. The Application Explorer requires Visual Studio and a full development environment. The built-in table browser shows one table at a time with raw field names.
That gap is exactly why we built XPT Data Explorer — a free, browser-based schema tool that gives you the complete Business Central data model in one place.
The Business Central Schema Problem
Business Central has over 2,000 tables. Each table can have hundreds of fields. Fields have data types, primary key flags, FlowField calculations, and table relations that link them to other tables. Understanding this schema — how tables connect, where data lives, what type each field is — is fundamental to every BC implementation, customisation, and data migration.
But until now, there hasn't been a single place to browse it all. Here's what developers and consultants have been using:
- Visual Studio + AL Language — powerful but requires a full development environment and a BC server connection
- Page Inspection in BC — shows which table backs a page, but only one table at a time
- Microsoft Learn documentation — comprehensive but scattered across hundreds of pages, often out of date for extensions
- Chrome extensions (Table Browser Caller) — require you to be logged into a BC environment, show raw field names with no context
- Jet Reports data dictionary — an Excel download, but static and can't show custom or extension tables
- bcentral.dev — generates ERD diagrams but requires uploading your solution files
None of these give you the simple thing you actually want: open a browser, search for a table, see every field with its type, primary key status, FlowField class, and relations to other tables.
The Free Schema Browser
XPT Data Explorer gives you exactly that. Open it in your browser — no login, no installation, no development environment — and you get:
Every Table
All 2,000+ standard BC tables, searchable by name or ID, filterable by category. Each table shows its record count from the standard Cronus demo company, so you can see which tables are heavily populated and which are configuration-only.
Categories include Sales, Purchasing, Inventory, General Ledger, Warehouse, Manufacturing, Service, Fixed Assets, Human Resources, Jobs, and more.
Every Field
Select a table and see every field with:
- Field number — the BC field ID used in AL code
- Field name — the caption as it appears in the BC interface
- Data type — Code, Text, Decimal, Integer, Date, DateTime, Boolean, Option, BLOB, GUID, and more. Colour-coded for quick scanning.
- Field class — Normal (stored in the database) or FlowField (calculated at runtime). This distinction is critical for query performance.
- Primary key — clearly marked with a PK badge
- Table relation — if the field links to another table, it shows as a clickable link. Click it to navigate directly to that table.
Table Relations
Table relations are the backbone of the BC data model. They define how tables connect — how a Sales Line links to its Sales Header, how a Customer Ledger Entry links back to the Customer table, how an Item Ledger Entry connects to both the Item and the Location.
The Schema Explorer shows both outbound relations (tables this table points to) and inbound references (tables that point to this table). Click any relation to navigate to it, building up an understanding of the data model as you go.
FlowFields Explained
FlowFields are unique to Business Central. Unlike normal fields that store data in the database, a FlowField is calculated on the fly by summing, counting, or looking up data from related tables.
For example, the Inventory field on the Item table is a FlowField — it doesn't store a number. Instead, BC calculates it by summing the Quantity field on all Item Ledger Entries for that item. Every time you read the field, BC runs that calculation.
This matters because:
- Including FlowFields in queries adds processing time — roughly proportional to the number of records
- FlowFields can't be filtered on directly — you need to use the underlying table instead
- FlowFields don't appear in SQL — if you're doing direct database reporting, you won't see them
The schema browser clearly marks every FlowField so you always know what you're working with.
Interactive ERD Diagrams
Beyond browsing fields, you can generate entity-relationship diagrams for any table:
- Go to the Schema tab in the Data Explorer
- Select a table (e.g. Sales Header, Customer, Item)
- Click ◈ Diagram
- A panel shows every relation — check the ones you want to visualise
- Drag table cards into your preferred layout
- Click Export PNG to download a presentation-ready diagram
This is different from other ERD tools because you choose which relations to display. A table like Item has dozens of relations, but for a specific implementation you might only care about five. The selective approach keeps diagrams clean and readable instead of producing unreadable spaghetti.
The diagrams are modern and clean — each table card shows the table name, ID, category colour, record count, primary key fields, and foreign key fields. Connection lines are labelled with the field name that creates the relationship.
Field Cross-Reference
One of the most useful features for data migrations and impact analysis: click any field to see a cross-reference of every table in BC that uses it.
For example, click the "No." field on the Customer table and you'll see every table that has a relation pointing to Customer.No — Sales Header, Sales Line, Customer Ledger Entry, Service Header, and dozens more. This tells you the full impact of any change to that field.
Query Builder with Live Data
The schema browser isn't just documentation — you can query live data. The free tier runs against Microsoft's standard Cronus demo company:
- Select fields to include in your query
- Add filters using standard BC filter syntax (ranges, wildcards, multiple values)
- See a performance estimate before running
- View up to 100 rows of results
- Export to CSV
This is useful for understanding how tables are populated in a standard BC installation — which fields contain data, what the values look like, and how records relate to each other.
Common BC Schema Questions Answered
Where does BC store customer data?
The Customer table (#18) is the master record. Related data lives in Customer Ledger Entry (#21) for transactions, Sales Header (#36) and Sales Line (#37) for open documents, and Sales Invoice Header (#112) for posted invoices.
How are GL entries structured?
The G/L Entry table (#17) stores every posted general ledger transaction. Before posting, entries live in Gen. Journal Line (#81). The G/L Account master is table #15.
Where is inventory data?
Item master data is in the Item table (#27). Every inventory movement creates an Item Ledger Entry (#32). Valuation data is in Value Entry (#5802).
What's the BC table numbering system?
Tables 1–49,999 are standard Microsoft objects. 50,000–99,999 is the legacy custom range. Tables above 100,000 are typically from extensions. The numbering within the standard range loosely groups by functional area — 1–99 for core master data, 5000+ for service, 5200+ for HR, 5600+ for fixed assets, 7300+ for warehouse.
How many tables does Business Central have?
A standard BC installation has over 2,000 tables. The exact number depends on the version and installed extensions. The XPT Schema Browser shows all tables including those from any installed extensions.
Get Started
The schema browser is completely free — no account, no sign-up, no installation:
- Open the Schema Browser — start browsing tables and fields immediately
- Customer Table — the most commonly referenced BC table
- G/L Entry Table — every posted general ledger transaction
- Item Table — the complete item master with 250+ fields
- Sales Header Table — sales orders and invoices
If you need to query your own BC data (not just the Cronus demo), the Pro plan lets you connect your own environment from £29/month.
XPT Data Explorer is built by Xpertly Ltd for Business Central developers, consultants, and analysts. The schema browser is free and always will be.