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100+ Free MB-820 Practice Questions

Pass your Microsoft Certified: Dynamics 365 Business Central Developer Associate (MB-820) exam on the first try — instant access, no signup required.

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Question 1
Score: 0/0

Which test codeunit attribute marks a procedure as a test that the Test Toolkit will execute?

A
B
C
D
to track
2026 Statistics

Key Facts: MB-820 Exam

40-60

Exam Questions

Microsoft

700/1000

Passing Score

Microsoft (scaled)

100 min

Exam Duration

Microsoft

$165

Exam Fee

Microsoft (USD)

35-40%

Largest Skill Area

Develop by using AL objects

Annual

Renewal

Free on Microsoft Learn

MB-820 is an Associate-level Microsoft developer exam (40-60 questions, 100 minutes, 700/1000 to pass, $165 USD). Largest skill area: Develop by using AL objects (35-40%). The credential validates AL extension development for Business Central — Microsoft's leading SMB ERP — and is renewed annually free on Microsoft Learn.

Sample MB-820 Practice Questions

Try these sample questions to test your MB-820 exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In Business Central, what is the recommended approach to add a new field to the standard Customer table without modifying the base application?
A.Edit the Customer table object directly in the base app
B.Create a tableextension object that targets the Customer table
C.Create a new table that links to Customer through a primary key
D.Use a configuration package to inject the field at deployment
Explanation: In modern Business Central (AL), all customizations to standard tables are made through tableextension objects. A tableextension targets the base table (in this case Customer) and adds new fields, keys, and field groups without modifying the source table. Direct edits to base app objects are not allowed in extensions.
2Which property in app.json declares the numeric range that AL objects in your extension are allowed to use?
A."objectRange"
B."idRange" or "idRanges"
C."applicationInsightsKey"
D."runtime"
Explanation: app.json uses "idRanges" (or the legacy single "idRange") to declare the object ID range(s) that the extension can use. AppSource extensions must own a Microsoft-assigned range, while per-tenant extensions use 50000-99999 or 50000000-99999999.
3You need to react when a user posts a sales order. Which approach is recommended in AL?
A.Modify codeunit 80 "Sales-Post" directly
B.Subscribe to a published event such as OnAfterPostSalesDoc in codeunit 80
C.Schedule a job queue entry that polls the Sales Header table
D.Use a control add-in to capture the click
Explanation: The supported AL pattern is to subscribe to events that the base application publishes (for example OnAfterPostSalesDoc in Sales-Post). Event subscribers run after Microsoft's logic without altering base code, which keeps the extension upgrade-safe.
4Which AL data type is designed to hold an arbitrarily large block of text or binary data such as a comment, JSON payload, or file content stored in a record?
A.Text[250]
B.Code[20]
C.BLOB
D.Variant
Explanation: BLOB is the AL field/data type for binary or large-text content. Use it with InStream/OutStream and CalcFields to read/write data such as long memos, attachments, or serialized JSON inside a record.
5Which page property must be set so a page can be exposed as a Business Central API for external integration via /api/<publisher>/<group>/v2.0?
A.PageType = API and APIPublisher / APIGroup / APIVersion / EntityName / EntitySetName
B.SourceTable = APIObject
C.UsageCategory = WebService
D.ServiceEnabled = true on the source table
Explanation: API pages require PageType = API plus APIPublisher, APIGroup, APIVersion, EntityName, and EntitySetName. These properties together build the OData V4 URL segment under /api/<publisher>/<group>/<version>/companies(...)/<entitySet>.
6What is the recommended way to read only a few fields from a record while iterating a large table to improve performance?
A.Call FindSet(true) to lock the rows
B.Call SetLoadFields with the fields you need before FindSet
C.Call CalcFields on every iteration
D.Increase the SQL command timeout
Explanation: SetLoadFields tells AL to retrieve only the listed fields from SQL (partial records). For wide tables this dramatically reduces network and memory usage compared with the default behavior of fetching every column.
7Which kind of code object encapsulates business logic and can be invoked from pages, reports, web services, or other codeunits?
A.Profile
B.Codeunit
C.Permission Set
D.Query
Explanation: Codeunits are AL containers for procedures and triggers. They are the standard place for business logic, and they can be called from pages, reports, web services, and other codeunits.
8In a Business Central report object, which two layout technologies are supported as built-in Microsoft layouts?
A.RDLC and Word
B.Crystal Reports and PDF
C.Power BI and Excel
D.XSLT and HTML
Explanation: AL report objects support RDLC (Report Definition Language Client) and Word layouts as the standard layout technologies. Excel layouts are also supported as a third option in modern versions, but Crystal, Power BI, and XSLT layouts are not.
9Which AL object is best suited for importing or exporting structured XML or fixed/variable text data files?
A.Query
B.XMLport
C.Codeunit
D.Page
Explanation: XMLports are AL objects designed for importing and exporting XML and text (fixed and variable) files. They define the structure (root, table, text/xmlattribute elements) and can be invoked from code.
10You want to store secrets such as an API key for an extension that should be hidden from other extensions and from end users. Which AL feature should you use?
A.A normal Text field on a setup table
B.IsolatedStorage with the appropriate DataScope
C.A global variable on a codeunit
D.A label translation file
Explanation: IsolatedStorage stores key/value data scoped to the extension/module/company/user. Other extensions cannot read another extension's IsolatedStorage values, and the values are not exposed in standard pages or table data — making it the recommended location for secrets such as API keys.

About the MB-820 Exam

The Microsoft Certified: Dynamics 365 Business Central Developer Associate (MB-820) exam validates skills designing, developing, testing, and maintaining AL extensions for Microsoft Dynamics 365 Business Central. Candidates extend tables and pages, build codeunits with events and interfaces, expose API pages, and integrate Business Central with external systems.

Questions

50 scored questions

Time Limit

100 minutes

Passing Score

700/1000 (scaled)

Exam Fee

$165 USD (Microsoft / Pearson VUE)

MB-820 Exam Content Outline

10-15%

Describe Business Central

Business Central architecture (components, capabilities, core/extensions approach, customization update lifecycle, online vs on-premises differences), Business Central apps (base app vs system app, app functionality, AppSource publishing process)

10-15%

Install, develop, and deploy for Business Central

Install and configure the AL development environment (app.json, launch.json, multiple workspaces), create/debug/deploy extensions in Visual Studio Code, multilanguage development with XLIFF, ongoing extension maintenance

35-40%

Develop by using AL objects

Tables and pages (Role Centers, page types, table/page extensions, enums and enumextensions), reports (RDLC/Word layouts, document reports, processing-only, multilanguage, request page), XMLports (properties, nodes, AL usage), codeunits (creation/access, events/triggers, interfaces, install/upgrade codeunits), permission sets and entitlements, queries (joins, filters, aggregation, query as report source)

15-20%

Develop by using AL

Customize the UI (profiles, views, user assistance, assisted setup, teaching tips, in-app tours, onboarding checklists), data process and document/master-data design patterns, AL fundamentals (custom procedures, data types, expressions, statements, built-in functions, variables, error handling, access modifiers, file management)

10-15%

Work with development tools

Test applications using the Test Toolkit and AL test codeunits/procedures (TransactionModel, handlers, [Test] attribute), telemetry monitoring/configuration, custom telemetry signals via Session.LogMessage, the in-client and VS Code performance profiler, analyzers (CodeCop, AppSourceCop, UICop, PerTenantExtensionCop)

10-15%

Integrate Business Central with other applications

Access REST services with HttpClient and JSON types, build/manage APIs with API pages, OData $expand/$select/$filter, OData bound and unbound actions ([ServiceEnabled]), Read Scale-Out for performance, OAuth 2.0/Microsoft Entra ID service-to-service authentication

How to Pass the MB-820 Exam

What You Need to Know

  • Passing score: 700/1000 (scaled)
  • Exam length: 50 questions
  • Time limit: 100 minutes
  • Exam fee: $165 USD

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

MB-820 Study Tips from Top Performers

1Master the AL object types end-to-end: table, tableextension, page, pageextension, codeunit, report, query, xmlport, enum, enumextension, interface, profile, permissionset, controladdin
2Practice the events model - subscribe with [EventSubscriber], publish with [BusinessEvent]/[IntegrationEvent], understand OnBefore/OnAfter patterns in the base app
3Build a sample API page with OData $expand and $filter, then call it from Postman or Power Automate using OAuth 2.0
4Get hands-on with app.json (idRanges, dependencies, applicationInsightsKey, resourceExposurePolicy) and launch.json for sandboxes and Docker containers
5Run the Test Toolkit, write test codeunits with [Test] and [HandlerFunctions], and capture code coverage from a real test run
6Profile a slow page with the in-client Performance Profiler, then optimize with SetLoadFields, SetCurrentKey, and well-designed FlowFields
7Enable CodeCop, AppSourceCop, UICop, and PerTenantExtensionCop on the project; understand which extension types each analyzer targets

Frequently Asked Questions

What is the MB-820 exam?

MB-820 is the Microsoft Certified: Dynamics 365 Business Central Developer Associate exam. It validates skills designing, developing, testing, and maintaining AL extensions for Microsoft Dynamics 365 Business Central, including tables, pages, codeunits, events, reports, XMLports, queries, API pages, and integrations.

How many questions are on MB-820?

MB-820 typically contains 40-60 questions completed in 100 minutes. The passing score is 700 out of 1000 (scaled). The exam fee is $165 USD via Pearson VUE (online proctored or test center).

What are the main domains of MB-820?

MB-820 covers six skill areas: Describe Business Central (10-15%), Install/develop/deploy for Business Central (10-15%), Develop by using AL objects (35-40%), Develop by using AL (15-20%), Work with development tools (10-15%), and Integrate Business Central with other applications (10-15%). The largest area is Develop by using AL objects.

Are there prerequisites for MB-820?

No formal prerequisites, but Microsoft recommends applied knowledge of Business Central, the AL language, the development environment, and AppSource. Familiarity with source control, CI/CD, telemetry, and one or more years of AL extension development is highly recommended.

Does MB-820 certification expire?

Yes - Microsoft Associate-level certifications including MB-820 must be renewed annually by passing a free renewal assessment on Microsoft Learn. The renewal focuses on changes to AL and Business Central since the previous exam version.

How should I prepare for MB-820?

Plan 60-100 hours of study over 6-10 weeks. Use the official Microsoft Learn MB-820 study guide, AL developer documentation, and a free Business Central sandbox. Build a small extension end-to-end (table extension, page extension, event subscriber, API page, test codeunit), then complete 100+ practice questions focused on Develop by using AL objects (35-40%).