Advanced Financial Management · Regulatory framework and processes

Defence Tactics Against Takeover Bids: Pre-Bid and Post-Bid Defences

Updated 11 October 2026 · Fact-checked

Defence tactics are steps a target board takes to resist an unwelcome takeover bid. Pre-bid defences make the company harder to buy. Post-bid defences respond to an actual offer. In the UK, the Takeover Code limits action that could frustrate a bid without shareholder approval. Judge each tactic by shareholder value.

Understand Defence Tactics Against Takeover Bids

A hostile bid is an offer made directly to shareholders that the target board does not recommend. The board may believe the price is too low, or it may want to protect its own position. AFM tests whether you can tell these motives apart.

Pre-bid defences are put in place before any offer arrives. They make a bid less likely or more costly. Examples are a poison pill, a staggered board, supermajority voting rules, cross-holdings, dual-class shares and a high share price kept up by good performance and investor relations. A poison pill (shareholder rights plan) lets existing shareholders, other than the bidder, buy shares cheaply once a trigger stake is crossed. This dilutes the bidder. Poison pills are common in the US. They are generally not used in the UK because of the Code.

Post-bid defences are used once an offer is made. Examples are:

Arguing the price is too low and publishing profit forecasts or a revaluation of assets.
Seeking a white knight, a friendly bidder the board prefers.
Seeking a white squire, a friendly party that buys a block of shares.
Making a Pacman defence, where the target bids for the bidder.
Raising a competition or regulatory objection.
Selling the crown jewels, the most attractive assets.
Increasing debt through a leveraged recapitalisation or a large buy-back.

The UK Takeover Code is built on the idea that shareholders decide on the bid, not the board. Once the board has reason to believe an offer is imminent or has been made, the frustrating action rule applies. The board must not take action that could frustrate the offer, or deny shareholders the chance to decide on its merits, unless shareholders approve it in general meeting. Typical examples are issuing shares, selling or buying material assets, or granting options. Actions under pre-existing contracts are not caught in the same way.

In exam answers, link every tactic to its effect on shareholder wealth. A defence that raises the final price helps shareholders. A defence that only entrenches management harms them. This links to agency theory.

Key rules to remember

Shareholder test of a defence: Gain from defence = Final offer price (or value if bid fails) − Original offer price; A defence is good for shareholders only if the final price, or the share price after a failed bid, beats the original offer. Allow for costs.
Frustrating action rule (UK Takeover Code): Board action that could frustrate an offer needs shareholder approval in general meeting; Applies when the board has reason to believe a bid is imminent or an offer has been made. Actions under earlier obligations are treated differently.
Dilution from a poison pill: Bidder's % after trigger = Bidder's shares ÷ (Existing shares + New discounted shares issued to others); Use it to show why the bidder's stake and control fall sharply. The bidder is excluded from buying.
Value of target as the board's counter-argument: Value per share = Estimated equity value ÷ Number of shares; Use a DCF, P/E or asset value to argue the offer undervalues the company.

How to solve Defence Tactics Against Takeover Bids questions

Use this method for any scenario on a hostile bid. Always tie your advice to the facts given.

1Identify the bidder, the offer terms and the target board's stated reason for resisting.
2Test the offer: value the target using the data given (P/E, DCF, assets) and compare with the offer price.
3Classify possible defences as pre-bid or post-bid and name the specific tactic.
4Check each tactic against the frustrating action rule if the target is UK-listed or the Code is mentioned.
5Assess the effect of each tactic on shareholders: price, cost, risk and whether it entrenches management.
6Consider alternatives such as a white knight or a Pacman defence, with cost and feasibility (funding, size).
7Recommend one course of action with a clear reason and mention the agency issue.
8State professional judgement: what you assumed and what extra information you would need.

Quickest way: Three-column defence table in your plan

When to use it: When a Section A or B requirement asks you to evaluate or recommend defences against a bid.

Write three headings: Tactic, Effect on shareholders, Code issue.
List two or three tactics that fit the scenario only.
Add one line of numbers, such as the value per share against the offer.
Finish with a recommendation and one risk.
Write the answer in short paragraphs, each starting with the tactic name.

Common mistakes in Defence Tactics Against Takeover Bids

Listing every defence from memory without applying them to the scenario.
Students learn the list but not the judgement.
Fix: Choose only the defences that fit the facts, such as the target's size or its funding capacity, and explain why.
Ignoring the frustrating action rule for post-bid tactics.
Students treat all defences as freely available to the board.
Fix: State that in the UK, once a bid is expected or made, actions that could frustrate it need shareholder approval.
Saying defences always protect shareholders.
Confusing board interests with shareholder interests.
Fix: Show whether the tactic raises the price or only protects management. Mention agency theory.
Confusing a white knight with a white squire.
The names are similar.
Fix: A white knight makes a rival bid that the board prefers. A white squire buys a block of shares, without taking over.
Recommending a Pacman defence without checking affordability.
Students focus on the concept and skip size and funding.
Fix: Compare the target's size and borrowing capacity with the bidder's. A small target cannot realistically buy a larger bidder.
Treating poison pills as standard UK practice.
Textbook examples are mostly American.
Fix: Say poison pills are common in the US but conflict with the Code's approach in the UK, so they are not available there without shareholder approval.

Worked examples

Example 1

Alpha plc offers $4.50 per share for Beta plc, which has 40 million shares. Beta's board rejects the offer. Beta's shares traded at $3.60 before the bid. Beta's earnings are $12 million and the sector P/E ratio is 13. Evaluate whether Beta's board has a valuation case for rejecting the offer.

Show the solution

Value Beta using the sector P/E: equity value = 12m × 13 = $156m.
Value per share = 156m ÷ 40m = $3.90.
Compare with the offer: $4.50 is above $3.90 by $0.60.
Compare with the pre-bid price: $4.50 is above $3.60 by $0.90, a premium of 0.90 ÷ 3.60 = 25%.
The offer exceeds both benchmarks, so a pure valuation case for rejection is weak on this data.

Answer: On a sector P/E basis Beta is worth $3.90 per share. The offer of $4.50 is $0.60 higher and a 25% premium to the pre-bid price. The board's valuation case is weak unless it can show growth or synergies not captured by the P/E. It might argue the sector P/E understates Beta's prospects, or negotiate a higher price.

Example 2

Gamma plc is UK-listed. After Delta plc announces a hostile offer, Gamma's board proposes to issue new shares to a friendly investor and to sell its most profitable division. Advise on the Code position and on the likely effect on shareholders.

Show the solution

Identify that an offer has been made, so the frustrating action rule applies.
Issuing shares to a friendly investor acts as a white squire move. It could frustrate the offer by diluting Delta's stake.
Selling the most profitable division is a crown jewels defence. It could frustrate the offer by removing what attracts the bidder.
Both actions could frustrate the offer, so the board needs shareholder approval in general meeting before acting.
Assess shareholder effect: the actions may prompt Delta to withdraw or to raise its price, but may also leave shareholders without an offer and with a weaker company.
Raise the agency issue: management may be protecting jobs rather than shareholder value.

Answer: The board should not carry out either action without shareholder approval in general meeting. Both could frustrate the offer. The board should instead publish a reasoned case on value, consider a white knight, and let shareholders decide. Defences are justified only if they are likely to improve the price or outcome for shareholders.

Exam tips

Always name the tactic, then say what it does and how it affects shareholders. Naming alone earns little.
Mention the Takeover Code's frustrating action rule whenever a UK target board takes steps after a bid appears.
Use any numbers in the case to test the offer price. A valuation comparison is the strongest counter-argument.
Raise agency theory and ethics: directors may defend for self-interest. This earns professional skills marks.
Recommend one clear course of action. Examiners reward judgement, not long lists.

Practice questions from Regulatory framework and processes

Defence Tactics Against Takeover Bids in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Defence Tactics Against Takeover Bids: frequently asked questions

What is the difference between pre-bid and post-bid defences?

Pre-bid defences are set up before any offer, to make the company harder or costlier to buy. Examples are poison pills and staggered boards. Post-bid defences respond to an actual offer, such as finding a white knight, a Pacman defence or arguing the price is too low.

What is a poison pill and a white knight?

A poison pill lets existing shareholders, other than the bidder, buy shares cheaply once the bidder's stake passes a trigger. This dilutes the bidder. A white knight is a friendly company the target board prefers to the hostile bidder and which makes a rival offer.

What is the Pacman defence?

The target tries to bid for the company that is bidding for it. It only works if the target can fund the purchase. It is most realistic when the two companies are similar in size.

What is the frustrating action rule?

Under the UK Takeover Code, once a board has reason to believe a bid is imminent or an offer has been made, it must not take action that could frustrate the offer without shareholder approval in general meeting. The aim is to let shareholders decide on the bid.