Onesys - The new home of Sage Coretime

Coretime - a brief history

Coretime was acquired by Onesys from Sage Group PLC on 29th May 2020. Before this purchase, the product was known as ‘Sage Coretime’.

Onesys are one of Sage’s largest and most successful business partners with offices throughout the UK.

Prior to this acquisition, Onesys had successfully supplied and supported many hundreds of Coretime customers over almost 20 years, having been appointed as the first reseller of the software in 2002. 

During that time, the product has evolved and grown into the functionally rich and robust product that you see today. The Onesys Development Team are now building on this platform to grow and improve the product based on customer feedback.

There are Coretime customers in the UK, Eire and around the world, with deployments ranging from a few users through to hundreds of fee earners in multiple offices. These include a number of blue chip clients.

Onesys also have a fully accredited and well-resourced team supporting Coretime, including experienced consultants to assist with implementation and training requirements. We now have more than 20 people working in the Coretime division. 

Sage Developer

Onesys are also Sage Developers and can integrate with other software as well as providing other services such as developing custom reports to your specification. We have lots of experience of doing both.

Because we supply a wide range of other Sage software including Sage 50, Sage 200 and Sage CRM, many of our clients choose Onesys as a single point of contact across all their Sage software.

You can read about some of our clients and their experience of working with us in our Case Studies.

Sage Business Partner

We specialise in supplying Sage software and we are also the largest UK partner of Global Business Systems. We also supply a number of other bespoke systems. We have partnerships with a number of other key vendors such as Version One, IBM and Microfocus. 

Onesys supply complete, distribution, manufacturing and service sector software systems as well as accounting, resource planning and project management systems. Find out more about our full range of software solutions at


Excellent Working Relationships

We value long-term relationships with our clients. Our approach is to clearly identify what you are trying to achieve and then provide a solution which can meet your objectives. Our friendly, professional training and support is an important part of our service to you.

Some of our clients have been with us for over 20 years. Onesys are by far the largest and most experienced supplier of Sage Coretime in the UK with thousands of satisfied users.

Find out about the Sage Coretime Team and the Onesys Vision, Mission & Culture

Get in touch if you would like to discuss your business objectives and how Sage Coretime can help.

Coretime Roadmap

At Onesys we are always striving to enhance Coretime and give our customers competitive advantage. See what is coming soon below:


ActiveX Invoice Settings

No longer a requirement to use Internet Explorer or ActiveX to generate sales invoices and statements. All major browsers are now compatible (including Edge)

Sage 50 Link Improvements

  • Internal Server error that occurred using the embedded version of the link has been fixed
  • Improved the narrative on Sales Invoices
  • Additional options to provide more clarity with Tax codes

New Coretime Reports

  • ​Budget v Actual
  • Job Profitability

New User Interface

New Coretime look and feel. There has been a refresh of the menu bar giving the system a fresh, clean look. 

Invoice Manager (Embedded)

For automated, bulk distribution of PDF invoices. Ideal for Coretime users that want to accelerate the distribution of their Sales Invoices.

This has now been embedded into the Coretime product and enabled in the licence string. Please note there is an additional charge for this module. 


Resource Planner

The Resource Planner is a rough-cut capacity planning tool that is designed to help companies manage forecasted demand based on Projects that are in flight as well as those in the pipeline. This is in addition to the existing Staff Planner tool that offers more detailed scheduling. 

Coretime CRM

Coretime CRM is designed to offer Communication Management, Task Management and Opportunity Management for companies with basic CRM requirements. For companies demanding greater functionality, the Coretime > Sage CRM integration is already available.


This was the most requested item in the Coretime Survey performed in Q3 2020 and will extend existing Coretime Budget functionality to allow Quotes and Estimates to be produced.

Purge Utility

Will allow you to clean up and de-clutter your Coretime data.

Cash VAT Accounting


Coretime HR

Coretime HR will add basic Human Resource/Human Capital Management functionality removing the need for some customers to run a separate HR system. 

Fixed Fee Invoicing

Improve the workflow around the production and control of fixed-fee and stage-based invoices.

Sage Business Cloud Accounting Integration

Multi-client Invoicing

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