Construction payment in Northern Ireland: the same numbers, a different Act, and a way of counting days that runs the opposite way

Published 20 September 2026 · VariationFlow

Why the Construction Act does not apply in Northern Ireland, what the Construction Contracts (Northern Ireland) Order 1997 does instead, why every payment period is identical to Great Britain’s, and the one thing that is not: section 39 of the Interpretation Act (Northern Ireland) 1954 rolls a deadline off a Sunday or public holiday where section 116 excludes holidays from the count, which moves real dates on real jobs.

A Belfast fit-out, a London main contractor, a pay less notice served on the last possible day. Whether it was in time depends on a question almost nobody on either side asks, because both sides assume the answer: which Act are we under, and how does it count days? Great Britain and Northern Ireland run the same payment figures on genuinely different machinery, and the difference is not in the numbers. It is in the counting, and it runs the opposite way.

The Construction Act does not apply here

Part II of the Housing Grants, Construction and Regeneration Act 1996, the part that contains every payment and adjudication provision, does not extend to Northern Ireland. Section 148(3) says so, and the revised text on legislation.gov.uk carries the extent restriction on Part II where the Act as a whole extends to Northern Ireland as well. That is also why section 116, the reckoning provision, speaks of a bank holiday “in England and Wales or, as the case may be, in Scotland” and then stops.

The parallel regime is the Construction Contracts (Northern Ireland) Order 1997, amended by the Construction Contracts (Amendment) Act (Northern Ireland) 2011 with effect from 14 November 2012 to mirror the 2009 changes made in Great Britain, with the Scheme for Construction Contracts in Northern Ireland Regulations 1999 behind it as the default terms.

It follows the site, not the head office

The split is clean and mutually exclusive. The Act applies to contracts relating to the carrying out of construction operations in England, Wales or Scotland. The Order applies to operations in Northern Ireland. So a Belfast job run by a London company is on the Order and not on the Act at all, and a Liverpool job run by a Belfast company is on the Act. The question is where the work is, not where either party is registered, and on a business with sites both sides of the water it is a per-project answer rather than a company-wide one.

Every number is the same

Read the Order article by article against the Act and the figures do not differ anywhere. Forty five days for the stage payment threshold. Five days for the payment notice after the due date. Seven days for the pay less notice before the final date, and seven for a notice of intention to suspend. Seven days from an adjudicator’s decision. Seventeen days to the final date under the Scheme, and twenty eight days for the Scheme’s relevant period, with the same later-of rule on the due date. Not one of them differs.

That sameness is exactly what makes the difference dangerous. Anything that checks arithmetic gives the same answer in Belfast as in Birmingham, so nothing flags the problem. A subcontractor working both sides can run the same spreadsheet on both and be wrong on one of them without any sign that they are.

The counting is what changes, and it inverts

The Order has no reckoning provision at all. Nineteen articles, and where Great Britain puts section 116 between service of notices and Crown application, the Order goes straight from article 14 to article 15. Neither the 2011 Act nor the Scheme adds one. Instead article 2(1) applies the Interpretation Act (Northern Ireland) 1954, whose section 39 does the job, and section 39 is a roll rather than an exclusion.

• Section 39(2): the day counted from is excluded. Same as section 116(2), so no difference there.
• Section 39(3): the last day is included.
• Section 39(4): where the time limited expires or falls upon a Sunday or a public holiday, it extends to the first following day that is neither.
• Section 39(8): a public holiday includes Christmas Day, Good Friday and any bank holiday.

Compare that with section 116(3), which EXCLUDES Christmas Day, Good Friday and bank holidays from the count wherever they fall. The difference is a holiday sitting in the middle of a period. In Birmingham that day does not count and the deadline moves a day later. In Belfast it does count and the deadline does not move. Run the Act’s rule on a Northern Irish job and you produce a date one day too late for every holiday inside the period, which is precisely how a late pay less notice comes to look timely and a payee loses a notified sum it was entitled to.

And Saturday is not in section 39

Only Sunday is. Section 39(6)(b) confirms it by defining a week-day as a day which is not a Sunday. So a Northern Irish deadline can fall on a Saturday and stand, exactly as a Great Britain deadline can. Rolling a Saturday pay less deadline forward to the Monday is a mistake in both jurisdictions, and it is the mistake that makes a late notice look valid, which is the direction that costs the payee the money.

Two things that are genuinely unsettled

How far section 39 reaches is arguable. Section 2(1) of the 1954 Act applies it to an “enactment”, which section 1(1) defines as an Act of the Northern Ireland Parliament or Assembly or an instrument made under one. An Order in Council made under the Northern Ireland Act 1974 is neither, which is why article 2(1) of the Order applies the 1954 Act expressly. That settles the Order’s own periods and says nothing about the Northern Ireland Scheme, which is made under the Order rather than under an Act and has no application provision of its own. The half that matters is agreed either way, though: nothing in Northern Irish law excludes a holiday from the count. Only the roll is arguable.

The second is contractual. On a JCT form used in Northern Ireland, the contract’s own reckoning clause would displace the statutory one for the contractual periods, and the England and Wales editions are not JCT’s Northern Ireland adaptation. Check which text you have signed before assuming either rule governs the contractual dates.

One more trap in the Northern Ireland Scheme

The Scheme for Construction Contracts in Northern Ireland Regulations 1999 is published as made and there is no revised consolidation, so the version you will find still reads “notice of intention to withhold payment”, which the 2011 Act replaced. The substituted paragraphs live only in the amending instrument of 2012, which spells the figures as words: not later than five days after the payment due date, and not later than seven days before the final date. If you are searching the 1999 text for “5 days” you will not find them, and you will be reading a superseded rule without any sign that you are. The 2012 amendments also reach only contracts entered into after 14 November 2012, which is a second date cliff to check on a long-running framework.

VariationFlow asks where the site is rather than where the company is, and reckons every payment date under the rule that applies there: section 116 in England, Wales and Scotland, and section 39 of the Interpretation Act (Northern Ireland) 1954 on a Northern Irish job, with the correct regional bank holiday list behind each. This guide is general information about the Order and the Act, not legal advice, and a live dispute about whether a notice was in time is worth an hour with a construction solicitor who practises in the jurisdiction the site is in.