Retention Release Schedules: 6+6 vs 12 Months Explained

One of the most important details in any construction contract is the retention release schedule. It determines when the money withheld from your payment applications gets returned to you. Get it wrong, and you could be waiting months longer than necessary for money that is rightfully yours.

What Is a Retention Release Schedule?

A retention release schedule defines when retained money is paid back to the subcontractor after practical completion of the project. The schedule is agreed in the contract and typically follows one of two standard patterns.

The 6+6 Schedule

The 6+6 retention release schedule is the most common in UK construction. It works like this:

1. 50% released at 6 months after practical completion
2. 50% released at 12 months after practical completion (end of defects liability period)

Example

Contract value: £100,000 with 5% retention (£5,000 total held)

• Practical completion: 1 January 2026
• 1 July 2026: first release of £2,500 (50%)
• 1 January 2027: second release of £2,500 (50%)

Why 6+6 Is Popular

The 6+6 schedule benefits both parties:

• For subcontractors: you get half your retention back sooner, improving cash flow
• For clients: they retain some insurance during the full defects liability period while releasing cash earlier

The 12-Month Schedule

Under a 12-month retention release schedule, the full retained amount is released in one payment at the end of the defects liability period:

1. 100% released at 12 months after practical completion

Example

Using the same £100,000 contract with £5,000 retention:

• Practical completion: 1 January 2026
• 1 January 2027: full release of £5,000

When 12-Month Schedules Are Used

• Some JCT Minor Works contracts default to 12 months
• Clients who want maximum protection during the defects period
• Projects where the defects liability period is 12 months or less

6+6 vs 12 Months: Which Is Better?

From a subcontractor's perspective, 6+6 is almost always preferable:

• Cash flow: you receive half the retention 6 months earlier
• Risk reduction: less money at risk if the client becomes insolvent before the 12-month mark
• Industry norm: 6+6 is the standard in most JCT and NEC contracts

If your contract specifies a 12-month schedule, it is worth negotiating for 6+6 during the contract stage, especially on larger value projects where the retained sum is significant.

Custom Release Schedules

Some contracts use custom retention release schedules that do not follow the standard patterns. These might include:

• Phased releases tied to specific project milestones
• Different timescales (e.g. 3+9 or 6+18)
• Releases tied to certification rather than calendar dates
• Partial releases on sectional completion of large projects

Custom schedules require careful tracking to ensure you claim each release when it falls due.

How to Track Release Dates

Missing a retention release date means the money sits with the client for longer. Here is how to stay on top of it:

1. Record the practical completion date as soon as it is certified
2. Calculate release dates based on the contract schedule (6+6 or 12 months)
3. Set reminders at least 2 weeks before each release date so you can issue a formal request
4. Follow up in writing if payment is not received within 7 days of the release date
5. Use software to automate the tracking; BuildQS calculates release dates and sends reminders automatically

Setting a Company Default

In BuildQS, you can set a company-wide default retention release schedule in Settings > Company Preferences. This means every new project automatically uses your preferred schedule (6+6 or 12 months), saving you from setting it manually each time. You can always override it on individual projects.

Frequently Asked Questions

What triggers the retention release clock?

The release schedule starts from the date of practical completion (or sectional completion if the contract includes that provision). This date is usually certified by the contract administrator or agreed between the parties.

What if practical completion is disputed?

If there is a dispute over whether practical completion has been achieved, the retention release dates may be delayed. It is important to get practical completion certified formally in writing to avoid ambiguity.

Can I claim interest on late retention releases?

Yes. Under the Late Payment of Commercial Debts Act, you are entitled to statutory interest on late payments, including late retention releases. The rate is 8% above the Bank of England base rate.

What happens to my retention if the client goes insolvent?

Unfortunately, retention money is not held in trust (unless the contract specifically requires it). If the client becomes insolvent, your retention is treated as an unsecured debt, and you may receive little or nothing. This is one reason why 6+6 is better than 12 months; you recover half sooner.