Most employees accept whatever annual raise their employer offers — typically 2-4% in UK. Negotiated raises (asking explicitly for more based on performance and market data) often produce 6-12% raises. The compounding over a career is dramatic.
How to negotiate annual raise
Document specific accomplishments and market data before the conversation. Schedule meeting specifically about compensation (not bundled into general review). State target: 'I'd like to discuss a 10% raise this year' rather than vague 'I'd like more'. Reference specific value created and market rates.
What managers usually do
Sometimes accept. Sometimes negotiate to lower number (5-8% rather than 10%). Sometimes deflect to other increments (title, vacation, project ownership). Even partial wins compound.
Five years of 2% raises produces lower salary than three years of 7% raises. The negotiation conversation costs nothing; not having it costs significantly.