Microsoft Dynamics SL (Solomon): Overview, Support & Migration

Microsoft Dynamics SL (Solomon)

Microsoft Dynamics SL — the product most long-standing users still call Solomon — is a legacy on-premise ERP system built for project-driven small and mid-sized businesses: professional services firms, specialty contractors and government contractors. Its distinguishing strength was never breadth; it was depth of project accounting. Microsoft stopped releasing new SL versions after Dynamics SL 2018, and extended support ends on 11 July 2028. Unlike the NAV-to-Business-Central path, there is no single like-for-like successor to SL — which makes the migration decision genuinely harder than most vendor messaging admits.

Updated July 2026. ERP Research is independent and vendor-neutral — no vendor pays for placement or ranking.

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That share is why an on-premise product reaching end of life is a live commercial problem rather than a historical footnote. A meaningful base of on-premise systems is still running real businesses, and each fixed support deadline converts a slice of it into a funded migration project.

Solomon, Solomon IV, Dynamics SL: The Naming, Explained

The naming confuses almost everyone who inherits one of these systems, because four different names describe the same product lineage:

"SL" is the abbreviation Microsoft assigned to the Solomon line when it grouped its acquired ERP products under the Dynamics brand — alongside GP (Great Plains), NAV (Navision) and AX (Axapta). It is not an acronym for a product feature, which is the answer to a question a surprising number of people search for.

If you have inherited a system described as "Solomon", "Solomon IV", "Solomon 6.0" or "Solomon accounting software", you are running an earlier release of the same product now called Dynamics SL, and the same end-of-support timeline applies to whichever version you are on.

Dynamics SL Modules & Features

SL is licensed as a set of module series. The project and field service series are what distinguished it from the rest of the Dynamics family.

Financials

General Ledger, Accounts Payable, Accounts Receivable, Cash Manager, Currency Manager and multi-company consolidation. Standard mid-market financials for their era.

Project Management & Accounting

The core of the product. Project Controller holds the project and task structure and the cost and revenue ledger; Project Allocator handles overhead and burden allocation rules; Flexible Billings generates time-and-materials, fixed-price, cost-plus and milestone invoices; reporting and notification modules sit on top.

Time & Expense

Timesheet and expense entry coded directly to projects and tasks — the data-capture layer that makes the project accounting work.

Field Service Management

Service Contracts, Service Dispatch, Equipment Maintenance and Flat Rate Pricing. This series supported contract-based service businesses and gave SL a foothold in field service before dedicated FSM products matured.

Distribution

Inventory, Purchasing, Order Management, Bill of Materials and Shipping — present and functional, but never SL's centre of gravity.

Payroll & Human Resources

US payroll processing with project-coded labour distribution, which mattered for contractors allocating labour cost across jobs.

Customisation & Reporting

Customization Manager for screen and business-logic changes, Crystal Reports for reporting, and the browser-based front ends added in later releases.

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Dynamics SL Support & End-of-Life Timeline

Dynamics SL is governed by Microsoft's Fixed Lifecycle Policy. Dynamics SL 2018 — the final release — moved from mainstream support to extended support on 9 January 2024, and extended support is scheduled to end on 11 July 2028.

One detail is worth knowing because it has caused genuine confusion: mainstream support was originally scheduled to end in July 2023, and Microsoft extended it by roughly six months to January 2024. The extended support end date of July 2028 did not move. If you read an older article citing a 2023 mainstream date, it is describing the superseded schedule.

What extended support means in practice:

• Security updates only. No new features and no design changes.
• Year-end regulatory updates have stopped. Microsoft's Dynamics Lifecycle FAQ ties tax and regulatory releases to the Mainstream Support phase, so they ended with mainstream support in January 2024; the final year-end payroll and Accounts Payable updates were delivered in December 2023. Payroll tax tables, wage bases and 1099 thresholds now have to be maintained manually — a live compliance consideration.
• A hard stop in July 2028. After that date there are no security updates, which becomes an information-security and audit problem, not just an IT one.
• Existing customers can generally still transact. Adding users or modules to an installed estate has typically remained possible during extended support; confirm your specific entitlement against your own agreement.

Every SL release earlier than 2018 — SL 2015, SL 2011, SL 7.0 and the Solomon-branded versions before them — is already past its extended support date. Lifecycle dates can be revised by Microsoft, so verify the current schedule against Microsoft's official lifecycle documentation or with your partner before building a plan around it.

Why There Is No Like-for-Like Successor to Dynamics SL

This is where SL differs from the rest of the legacy Dynamics family, and where most migration advice is too simple.

When NAV reached end of life, Microsoft had a direct answer: Business Central, built on the same codebase, with a recognisable functional map. SL has no equivalent. No single Dynamics 365 product reproduces SL's project accounting as a like-for-like map. The capabilities exist across the family — Dynamics 365 Finance with Project Operations covers burden and overhead allocation and project revenue recognition — but Business Central, the destination Microsoft actually points SL customers to, is materially lighter, and reaching SL-equivalent depth means moving up to a heavier platform than most SL sites are sized for. So SL sites face a real choice rather than an upgrade:

One product detail worth getting right, because it is commonly misstated: Project Operations does not deploy on Business Central. Microsoft's deployment options are Project Operations Core on Dataverse and Project Operations integrated with the finance and operations apps. Business Central's project capability is its own native Projects module (formerly Jobs); any link between the two is custom integration, not a shipped Microsoft configuration.

The honest framing: treat this as a fresh ERP selection with a strong Microsoft incumbent advantage, not as a mandatory upgrade to a predetermined destination. The migrations that go badly are the ones where parity was assumed and a billing or allocation gap surfaced late.

How to Migrate from Dynamics SL

A realistic SL migration follows these steps:

1. Document how you actually bill. Before evaluating anything, write down every billing arrangement, allocation rule and revenue recognition method you run in SL, with a live example of each. This document is the single most useful artefact in the project, because it is the specification any successor has to satisfy.
2. Inventory version, customisations and integrations. Record your SL version, active modules, every Customization Manager change, every report the business depends on, and every integration. Expect to find reports nobody reads and customisations nobody remembers requesting.
3. Shortlist against project capability, not brand. Evaluate Business Central with its native Projects module, Dynamics 365 Finance with Project Operations, and at least one project-ERP specialist. Score them against the billing document from step one — use our ERP functional requirements framework to keep the comparison structured.
4. Demand a scripted demo of your hardest billing case. Not a generic product tour. Give each vendor your most awkward real contract and ask them to invoice it on screen. This is where genuine gaps surface.
5. Choose a partner with SL migration experience specifically. The SL partner community is smaller than GP's or NAV's, and generic Dynamics 365 experience is not the same as knowing what a Project Controller data model looks like. Find a Microsoft implementation partner who has moved an SL site before.
6. Plan data migration around projects, not just the ledger. Open projects, historical job cost, contract terms and work-in-progress balances are the hard part. Decide early how much project history moves and how much stays in a read-only archive.
7. Pilot, parallel-run, then cut over. Validate against live data, confirm reporting and billing parity, train users, and only then schedule go-live. Give yourself margin against the July 2028 date rather than running at it.

How Much Does Dynamics SL Cost?

Microsoft does not sell Dynamics SL to new customers, so there is no current list price for the product itself. The relevant number for any SL site in 2026 is what the replacement will cost.

Historically, SL was licensed perpetually — a base licence plus the module series described above, with user licences on top, and an annual enhancement plan charged as a percentage of licence value to entitle you to updates and support. Existing customers still carry that annual cost, and it is worth checking what it is actually buying you now that no new functionality is being released.

For replacement budgeting, see our Dynamics 365 pricing overview and Business Central pricing and costs guide, and budget implementation separately with our ERP implementation cost breakdown. Ask your partner explicitly about migration licensing concessions — Microsoft has periodically offered promotional terms to customers moving off legacy Dynamics products, and these are not always volunteered.

Industry Fit

Professional Services

SL's natural home. Engineering firms, architects, consultancies and IT services companies used it for utilisation, project margin and time-and-materials billing. See best ERP for professional services companies for current options.

Construction & Specialty Trades

Job costing, subcontractor management and progress billing made SL a fit for specialty contractors — mid-sized mechanical, electrical and similar trades rather than large general contractors.

Government Contracting

Cost allocation and audit-traceable project accounting gave SL a foothold among government contractors, a segment where Deltek and Unanet are now the specialist incumbents.

Field Service

Contract-based service organisations used the Field Service series for dispatch, service contracts and equipment maintenance alongside project accounting.

History

Solomon Software was based in Findlay, Ohio, growing out of TLB, Inc., a company founded in 1980 by Gary Harpst, Jack Ridge and Vernon Strong and later renamed Solomon Software. The product built its reputation on project and job-cost accounting for smaller organisations.

Solomon IV, the Windows rewrite, arrived in 1994, and in 1999 the company committed to an all-Microsoft technology stack — SQL Server for the database, Visual Basic as the development language and VBA for customisation. That decision made the product an attractive acquisition target.

Great Plains Software acquired Solomon in 2000. Microsoft then acquired Great Plains Software, completing the deal in 2001, which brought Solomon into Microsoft alongside Great Plains itself. The product was sold as Microsoft Business Solutions–Solomon — the last release under that name was Solomon 6.0 in October 2004 — before being rebranded with the release of Microsoft Dynamics SL 6.5 in December 2005, when Microsoft consolidated its acquired ERP products under the Dynamics name.

Development continued through SL 7.0, SL 2011, SL 2015 and SL 2018, which was the final release. Microsoft's investment moved to the Dynamics 365 line, and SL entered the managed decline it is now completing.

Frequently Asked Questions

What is Dynamics SL used for?

Dynamics SL is used for project-driven accounting: tracking cost and revenue against projects and tasks, allocating overhead and burden, generating time-and-materials, fixed-price and cost-plus invoices, and reporting job-level margin. It is most common in professional services firms, specialty contractors, government contractors and contract-based field service organisations.

Is Solomon the same as Microsoft Dynamics SL?

Yes. Solomon Software was the original independent company and product; Microsoft acquired it via Great Plains Software and rebranded it Microsoft Dynamics SL in December 2005, with the release of Dynamics SL 6.5. Systems described as "Solomon", "Solomon IV" or "Solomon accounting software" are earlier releases of the same lineage.

What does the SL in Microsoft Dynamics SL stand for?

SL is Microsoft's abbreviation for the Solomon product line. It is not an acronym describing a feature. Microsoft applied the same convention to its other acquired ERP products: GP for Great Plains, NAV for Navision and AX for Axapta.

Is Microsoft Dynamics SL being discontinued?

Effectively, yes. Dynamics SL 2018 was the final release and no new versions are planned. The product remains in extended support — security updates only — until 11 July 2028, after which it is unsupported.

When does support for Dynamics SL end?

Mainstream support for Dynamics SL 2018 ended on 9 January 2024, and extended support is scheduled to end on 11 July 2028. Earlier releases are already past their extended support dates. Confirm current dates against Microsoft's official lifecycle documentation before planning around them.

What replaces Microsoft Dynamics SL?

There is no direct one-to-one replacement. Microsoft directs SL customers to Dynamics 365 Business Central and has built first-party SL-to-Business-Central migration tooling. Larger or more complex project organisations often look instead at Dynamics 365 Finance with Project Operations, which Microsoft does not name in its SL guidance. Many SL sites also evaluate project-ERP specialists such as Deltek, Unanet, Acumatica and NetSuite.

Is Dynamics SL cloud-based?

No. Dynamics SL is an on-premise product. It can be hosted by a partner in a private or public cloud environment, which delivers remote access, but that is hosting rather than a multi-tenant SaaS product, and it does not change the July 2028 support deadline.

What was the last version of Dynamics SL?

Microsoft Dynamics SL 2018 was the final version, preceded by SL 2015, SL 2011 and SL 7.0. No release after SL 2018 is planned.

How long does a Dynamics SL migration take?

It varies with project accounting complexity, but SL migrations are typically scoped in quarters rather than weeks, because open projects, work-in-progress balances and billing rules all have to be reproduced and validated. Given the July 2028 deadline, starting the selection well ahead of the date leaves room for a parallel run.

Related Resources

• Microsoft Dynamics 365 Business Central — the most common SL migration destination
• Business Central Pricing & Costs — what the replacement will cost to license
• Microsoft Dynamics GP (Great Plains) — the sibling legacy Microsoft SMB ERP
• Microsoft Dynamics NAV (Navision) — the legacy product with a direct successor path
• Microsoft Dynamics AX — the enterprise-tier legacy Microsoft ERP
• Microsoft Dynamics 365 ERP — the modern Dynamics family explained
• Dynamics 365 Project Management Module — where SL's project function maps in Dynamics 365
• Best ERP for Professional Services Companies — alternatives for SL's core market
• Microsoft Implementation Partners — find a partner with SL migration experience
• ERP Implementation Cost Breakdown — budgeting the migration itself
• ERP Functional Requirements — scope the decision before you commit