Choosing Secondary Options

To choose NEC4 secondary Options, start with what could go wrong on this particular job, then select only the Options that deal with those risks. Each one moves risk or adds a process, and tenderers will price both, so an Option added out of habit is rarely free.

This guide uses NEC4 ECC numbering. Availability varies by form and edition, so check the full list of NEC secondary Options if you are using a different contract.

Ten questions to work through

Question	If yes, consider
Is the Act relevant to your UK construction work?	W2 and Y(UK)2. If not, W1
Could inflation move your costs significantly?	X1, on Options A to D
Is the Contractor part of a group, and is its covenant in doubt?	X4 or X13
Does the Client need parts of the works early?	X5
Does late finish cost the Client quantifiable money?	X7
Is early finish worth real money?	X6
Will the Contractor design, and is the Scope outcome-based?	X15, and read X9
Is BIM part of the job?	X10
Will funders or tenants want rights?	X8 or Y(UK)3
Could the Client's plans change before Completion?	X11

Combinations to watch

• X12 and X20: don't use both. Each Option's heading rules out the other.
• X1: only with main Options A to D.
• X3: only with Options A and B.
• X16: not with Option F.
• X22: only with Options C and E.
• W1, W2 and W3: pick one. It's a required choice, not an add-on.
• X7 with X6 or X5: no conflict, and they're often used together, with rates per section.

Starting points by project type

These are prompts for discussion, not recommendations. Your own risk and procurement rules decide.

Project (fictional)	Often considered	Why
Small Option A building job	W2, Y(UK)2, X7, X16	Payment law, a late-finish remedy and some security
Multi-year Option C infrastructure	W2, Y(UK)2, X1, X5, X7, X18, X15	Inflation, phasing and liability caps
Client-funded development with a funder and tenant	W2, Y(UK)2, X7, X8, Y(UK)3, X4	Third parties want direct rights
Public programme with early design input	W2, Y(UK)2, X22 with C or E, X12, Y(UK)1	Collaboration and supply chain payment
Process plant, judged on output	W2, Y(UK)2, X17, X7, X18	Performance matters as much as time

What each choice costs

Every Option has a price, even if nobody writes it down.

• Security (X4, X13, X16): premium costs, cash flow and bonding capacity. Requiring all three may be more than the Client's risk justifies.
• Incentives (X6, X20): the Client's budget has to allow for the amounts it might pay.
• Liability (X15, X18): the Contractor's tender may be lower, but the Client keeps more risk.
• Process (X10, X12, X22): people have to be available to run them. An Option no one operates is worse than none.

Common mistakes

1. Copying the last contract's list. Selections from NEC3 won't map neatly, because some numbers mean something different in NEC4. X19 is the clearest example.
2. Selecting without completing the data. Most Options need Contract Data entries or text in the Scope. If they're blank, the Option may not work.
3. Using a Z clause when an Option already exists. See writing Z clauses.
4. Ignoring subcontracts. Whatever you select in the main contract usually needs a matching decision below it. See back-to-back subcontracts.
5. Deciding before the main Option. The main Option affects which Options are open, so choose that first. See choosing a main Option.

A simple way to run the decision

1. List the project's top ten risks, and say who should own each.
2. Choose the main Option and the dispute Option.
3. Go through the table above and note a reason for each Option you choose.
4. Draft the Contract Data entries and Scope text for those Options.
5. Ask a commercial manager to read the result as a tenderer would.
6. Keep the reasoning, so that the next project reviews it and doesn't simply copy it.

Related guides

• NEC Secondary Options: X, Y, W and Z Clauses Explained
• Z Clauses: Writing Additional Conditions
• Common Z Clause Mistakes

This guide is general information in our own words, not legal advice. Your contract and its Contract Data always govern. NEC, NEC3 and NEC4 are trade marks of Thomas Telford Ltd; Contract Status is not affiliated with or endorsed by NEC.