Purchase Agreement Addendum (UK)
ADDENDUM TO PURCHASE AGREEMENT
This Addendum to Purchase Agreement (this “Addendum”) is entered into on [Addendum Date] between:
[Seller Name], of [Seller Address], [Seller City], [Seller Postcode], England and Wales (the “Seller”); and
[Buyer Name], of [Buyer Address], [Buyer City], [Buyer Postcode], England and Wales (the “Buyer”).
BACKGROUND
(A) The Seller and the Buyer entered into a Purchase Agreement dated [Original Agreement Date] for [Original Agreement Description] (the “Original Agreement”).
(B) The Parties now wish to vary certain terms of the Original Agreement by entering into this Addendum.
(C) This Addendum is entered into in accordance with the variation clause of the Original Agreement (where applicable) and is supported by fresh consideration as set out below.
NOW, THEREFORE, in consideration of the mutual promises and undertakings set out herein (including the consideration described in clause 1 below) and for other good and valuable consideration, the sufficiency and receipt of which the Parties hereby acknowledge, the Parties agree as follows:
1. CONSIDERATION
1.1 The Parties acknowledge that this Addendum is supported by the following consideration: [Consideration Description].
1.2 The Parties further acknowledge that each Party’s promise to be bound by the varied terms of the Original Agreement (as amended by this Addendum) constitutes good and sufficient consideration for the other Party’s corresponding promise.
2. GENERAL PROVISIONS
2.1 Continuation of Original Agreement. Except as expressly amended by this Addendum, all other terms and conditions of the Original Agreement shall continue in full force and effect and are hereby ratified and confirmed.
2.2 Conflict. In the event of any conflict or inconsistency between the terms of this Addendum and the terms of the Original Agreement, the terms of this Addendum shall prevail to the extent of the conflict or inconsistency.
2.3 Entire Agreement (as varied). The Original Agreement, as varied by this Addendum, constitutes the entire agreement between the Parties with respect to the subject matter thereof and supersedes all prior oral or written agreements, representations, and understandings.
2.4 Further Amendments. This Addendum may itself only be further varied in accordance with the variation clause applicable to the Original Agreement or by a further written agreement signed by both Parties.
2.5 Third Party Rights. A person who is not a party to this Addendum or the Original Agreement shall have no right under the Contracts (Rights of Third Parties) Act 1999 to enforce any of its terms.
2.6 Consumer Protection. Nothing in this Addendum removes or restricts any rights of a consumer Buyer under the Consumer Rights Act 2015, the Consumer Protection from Unfair Trading Regulations 2008, or any other applicable consumer protection legislation.
2.7 Governing Law. This Addendum and any dispute or claim arising out of or in connection with it shall be governed by and construed in accordance with the laws of England and Wales. Each Party irrevocably submits to the exclusive jurisdiction of the courts of England and Wales.
IN WITNESS WHEREOF, the Parties have executed this Addendum to Purchase Agreement as of the date first written above.
THE SELLER
Name: [Seller Name]
Address: [Seller Address], [Seller City], [Seller Postcode]
THE BUYER
Name: [Buyer Name]
Address: [Buyer Address], [Buyer City], [Buyer Postcode]
Seller
________________
Signature
Date: ________________
Buyer
________________
Signature
Date: ________________
What Is a Purchase Agreement Addendum (UK)?
A Purchase Agreement Addendum in the United Kingdom records the price, deposit, completion date, and title obligations for the transfer of an interest in land, with its requirements set by the Consumer Rights Act 2015.
Under English contract law, a contract can be varied by mutual agreement of the parties, provided the variation is supported by fresh consideration or is made by deed. The doctrine of consideration requires that each party to a variation must provide something of value in exchange for the other party's promise to be bound by the new terms. Common examples of consideration in a purchase agreement addendum include a buyer agreeing to pay an additional sum in exchange for the seller delivering goods earlier than originally agreed, or a seller agreeing to reduce the price in exchange for the buyer committing to purchase a larger quantity.
The requirement for consideration was confirmed by the Supreme Court in Rock Advertising Ltd v MWB Business Exchange Centres Ltd [2018] UKSC 24, which also confirmed that a 'no oral modification' (NOM) clause in a contract is generally enforceable — meaning that any variation must be made in the form specified in the original agreement (typically in writing and signed by both parties). A well-drafted addendum satisfies this requirement by documenting the variation in writing, identifying the parties and the original agreement, setting out the specific changes, and recording the consideration for the variation.
For consumer transactions, the Consumer Protection from Unfair Trading Regulations 2008 (CPR) impose additional obligations on traders when varying a purchase agreement, prohibiting misleading or aggressive commercial practices. The Consumer Rights Act 2015 continues to protect consumers' statutory rights regardless of any variation agreed in an addendum.
The legal framework governing the Purchase Agreement Addendum (UK) in United Kingdom draws on several key statutes and regulatory bodies. Under the Companies Act 2006, Companies House maintains the register of UK companies. Section 386 of the Companies Act 2006 sets accounting record obligations. The Competition and Markets Authority (CMA) enforces the Consumer Rights Act 2015. The Financial Conduct Authority (FCA) regulates financial services under the Financial Services and Markets Act 2000. The High Court of Justice has jurisdiction under the Senior Courts Act 1981. Parties executing a Purchase Agreement Addendum (UK) in United Kingdom should confirm the document reflects current law, including any amendments enacted since the original drafting date. The Companies Act 2006 sets the foundational requirements.
When Do You Need a Purchase Agreement Addendum (UK)?
A Purchase Agreement Addendum is appropriate whenever a buyer and seller in England or Wales have signed a purchase agreement and subsequently need to vary one or more of its terms, without wanting to draft an entirely new contract. Common situations in which a purchase agreement addendum is needed include: where the seller cannot meet the original delivery date and the parties agree a revised date; where material costs have increased since the agreement was signed and the parties agree a price adjustment; where the buyer wants to increase or decrease the quantity of goods ordered; where the specification of the goods needs to be changed due to a product update, shortage, or change in the buyer's requirements; or where the parties want to revise the payment terms to accommodate cash flow difficulties.
An addendum is also appropriate where the parties want to add new terms to the original agreement that were not initially contemplated — for example, adding a force majeure clause, an inspection and acceptance procedure, or additional warranty provisions.
In consumer transactions, an addendum should be used with care. The Consumer Protection from Unfair Trading Regulations 2008 prohibit traders from using pressure tactics or misleading practices to obtain a consumer's agreement to worse terms. Any variation that reduces the consumer's rights below those guaranteed by the Consumer Rights Act 2015 will be unenforceable. A consumer addendum should clearly explain the change being made, the consumer's right to refuse the variation and insist on the original terms, and any consequences of accepting or rejecting the variation.
For VAT purposes, if a variation changes the consideration for a taxable supply, the seller must issue a credit note or a revised VAT invoice under the Value Added Tax Act 1994 to correct the original VAT position.
What to Include in Your Purchase Agreement Addendum (UK)
A well-drafted Purchase Agreement Addendum for use in England and Wales should contain several key provisions that confirm the variation is legally binding and clearly understood by both parties.
The identification clause should clearly reference the original Purchase Agreement by its date and a brief description of its subject matter. This creates an unambiguous link between the addendum and the original contract and prevents disputes about which agreement is being varied.
The consideration clause is critical under English law. It should set out precisely what consideration each party is providing in exchange for agreeing to the variation. Without adequate consideration, the variation may not be enforceable unless it is executed as a deed or gives rise to an estoppel. The consideration clause should be drafted in terms that reflect the actual commercial exchange — for example, a payment, a concession, an additional obligation, or a benefit — rather than the nominal consideration of 'one pound' (which, while technically sufficient, may not reflect the true commercial intent).
The variation clauses should set out each specific change to the original agreement clearly and unambiguously. Best practice is to cite the specific clause number being amended and to state both the old and new wording, so that the effect of the variation is unmistakable. Ambiguous or broadly worded variations frequently give rise to disputes about whether a particular provision of the original agreement has been changed.
The continuation clause confirms that all terms of the original agreement not expressly amended by the addendum remain in full force and effect. This is essential to prevent the addendum from inadvertently replacing or undermining the original contract.
The conflict clause confirms that in the event of any inconsistency between the addendum and the original agreement, the addendum takes precedence. This prevents disputes about the interpretation of conflicting provisions. The governing law and jurisdiction clause (England and Wales) and the third-party rights exclusion under the Contracts (Rights of Third Parties) Act 1999 should be repeated in the addendum.
Additional compliance elements for a Purchase Agreement Addendum (UK) used in United Kingdom include: Under the Companies Act 2006, Companies House maintains the register of UK companies. Section 386 of the Companies Act 2006 sets accounting record obligations. The Competition and Markets Authority (CMA) enforces the Consumer Rights Act 2015. The Financial Conduct Authority (FCA) regulates financial services under the Financial Services and Markets Act 2000. The High Court of Justice has jurisdiction under the Senior Courts Act 1981. Forms-legal.com provides this template as a starting point for United Kingdom-compliant documentation.
Cite this page
Reference this free template in an article, syllabus, or research note:
Forms Legal. (2026). Purchase Agreement Addendum (UK) (United Kingdom) [Legal document template]. Forms Legal. https://forms-legal.com/uk/business/contracts/uk-purchase-agreement-addendum
"Purchase Agreement Addendum (UK) (United Kingdom)." Forms Legal, 2026, https://forms-legal.com/uk/business/contracts/uk-purchase-agreement-addendum.
@misc{formslegal-uk-purchase-agreement-addendum,
author = {{Forms Legal}},
title = {Purchase Agreement Addendum (UK) (United Kingdom)},
year = {2026},
howpublished = {\url{https://forms-legal.com/uk/business/contracts/uk-purchase-agreement-addendum}},
note = {Free legal document template. Based on Companies Act 2006}
}Also available for these jurisdictions:
Frequently Asked Questions
Under traditional English contract law, a variation to a contract requires fresh consideration from both parties to be binding. Consideration means each party must give or promise something of value in exchange for the other party's promise. A bare promise to accept less money or to perform different obligations (without receiving anything in return) is not supported by consideration and may not be binding. However, English law in this area is nuanced. The doctrine of promissory estoppel (established in Central London Property Trust Ltd v High Trees House Ltd [1947]) can prevent a party from going back on a promise to accept less, even without consideration, where the other party has relied on that promise to their detriment. The Supreme Court's decision in Rock Advertising Ltd v MWB Business Exchange Centres Ltd [2018] UKSC 24 confirmed that a 'no oral modification' clause in a contract is generally enforceable, meaning that any variation must be made in the manner specified in the original contract (typically in writing signed by both parties). It is therefore best practice to document any variation with a written addendum, clearly stating the consideration for the variation.
The Consumer Protection from Unfair Trading Regulations 2008 (CPR) implement the EU Unfair Commercial Practices Directive (as retained in UK law) and prohibit traders from engaging in unfair commercial practices towards consumers. The CPR apply to all stages of a commercial transaction, including any variation to a purchase agreement. A trader who pressures a consumer into accepting a variation — for example by threatening to cancel the contract unless the consumer agrees to worse terms — may be engaging in an aggressive commercial practice under regulation 7 of the CPR. Similarly, misleading a consumer about the effect of a variation (for example, by misrepresenting the new delivery date or price) may constitute a misleading action under regulation 5 of the CPR. Consumers who have been misled into entering a contract (or a variation) have statutory rights to unwind the transaction, obtain a discount, or claim damages under the Consumer Protection (Amendment) Regulations 2014. Traders must confirm that any variation to a consumer purchase agreement is explained clearly and honestly.
A 'no oral modification' (NOM) clause is a contractual term that requires any variation to the contract to be made in writing (and usually signed by both parties) in order to be effective. In Rock Advertising Ltd v MWB Business Exchange Centres Ltd [2018] UKSC 24, the Supreme Court confirmed by a majority of 4 to 1 that NOM clauses are generally enforceable under English law. This means that if the original purchase agreement contains a NOM clause, any oral agreement to vary the contract (such as a verbal agreement to extend a delivery date) will not be binding unless it is also recorded in a written addendum. The exception is where the party seeking to enforce the NOM clause has conducted itself in a way that gives rise to an estoppel — that is, where they have led the other party to rely on the oral variation to their detriment. In practice, this means that businesses should always use a written addendum to document any agreed variation to a purchase contract, to avoid uncertainty about whether the variation is legally binding.
No. Under section 13 of the Sale of Goods Act 1979, goods sold by description must correspond with their description. If the seller delivers goods that do not correspond with the agreed specification — even if the seller considers the substituted goods to be of equivalent or superior quality — this is a breach of the implied term as to description. The buyer is entitled to reject the non-conforming goods and claim damages. A seller wishing to change the specification of goods after the purchase agreement is signed must obtain the buyer's written consent. This consent should be documented in a written addendum to the agreement, and should address any consequential changes to the purchase price, delivery date, or warranty. In a consumer contract, the buyer has additional rights under the Consumer Rights Act 2015 if the goods delivered do not match the description, including the right to a full refund within 30 days.
A reduction in the purchase price in a UK purchase agreement should always be documented in a written addendum signed by both parties. This is important for several reasons: (1) under the principle established in Rock Advertising [2018], if the original agreement contains a no oral modification clause, an oral price reduction agreement may not be binding; (2) for VAT purposes, if the price reduction changes the VAT chargeable on the supply, the seller must issue a credit note or a revised VAT invoice in accordance with the Value Added Tax Act 1994 and HMRC's VAT Notice 700; and (3) if the price reduction is agreed in a context where the buyer was in financial difficulty, the liquidator or administrator of the buyer could later challenge the reduced price as a transaction at an undervalue under the Insolvency Act 1986 (section 238) if it is below the market value of the goods. A written addendum protects both parties by creating a clear record of the agreed variation and the commercial reasons for it.
This template is provided for informational purposes only and does not constitute legal advice. Laws vary by jurisdiction and change over time. Consult a qualified attorney for advice specific to your situation.Full disclaimer
Found an error? Let us knowRelated Documents
You may also find these documents useful:
Purchase Agreement (UK)
Create a detailed UK Purchase Agreement for goods, services, or mixed contracts under English law. Covers Sale of Goods Act 1979 implied terms, Supply of Goods and Services Act 1982, Consumer Rights Act 2015 for B2C transactions, VAT provisions, retention of title, and limitation of liability. Suitable for B2B and B2C commercial transactions in England and Wales.
Asset Purchase Agreement (UK)
Create a detailed UK Asset Purchase Agreement for the acquisition of business assets in England and Wales. Covers Companies Act 2006, TUPE Regulations 2006 for employee transfers, Transfer of a Going Concern (TOGC) VAT treatment, Taxation of Chargeable Gains Act 1992, seller warranties, completion accounts, price apportionment, and post-completion restrictions. Suitable for SME acquisitions and business asset sales.
Business Contract (UK)
Create a detailed UK business contract governed by the laws of England and Wales. Covers the Sale of Goods Act 1979, Supply of Goods and Services Act 1982, Late Payment of Commercial Debts (Interest) Act 1998, Contracts (Rights of Third Parties) Act 1999, Unfair Contract Terms Act 1977, and Consumer Rights Act 2015. Suitable for goods sales, service provision, and general commercial transactions.
Bill of Sale (England & Wales)
Create a legally sound Bill of Sale for England and Wales. Covers the sale of personal property between private individuals or businesses, with provisions for goods condition, warranty, delivery, and compliance with the Sale of Goods Act 1979 and Consumer Rights Act 2015. Supports cash, bank transfer, and cheque payments in GBP. Download as PDF or Word.