With 77% agreeing authenticity is now more difficult to judge before a candidate joins the business, employers are increasingly shifting evaluation into the probation window.
Across the 500 UK HR leaders surveyed, 74% say CVs and cover letters are less reliable than they were two years ago due to AI, and 75% report an increase in AI‑generated applications. That said, they aren’t naive to the uptick in AI generated applications, with 74% saying they are able to spot this clearly.
This trust gap is pushing organisations to refocus their assessment of talent into the first months of their employment. A substantial 77% say probation reveals more about true capability than interviews, while only 6% disagree.
As a result, many companies are redesigning their early‑employment experience: 42% have made probation more structured with stricter targets and checkpoints, and 37% now rely on probation as a “safety net” to identify hires who performed well during interviews but struggle on the job.
Matt Monette, UK&I Country Lead and Head of Expansion at Deel, said: “AI has widened the gap between how candidates present themselves and how they perform. Something that used to feel predictable - reviewing a CV, holding an interview - now feels less reliable. Employers are telling us they can only understand real capability once someone starts the job, and probation has become the moment where authenticity is finally visible. Probation is no longer a formality. It’s becoming the defining stage of hiring in an AI‑driven world.”
A time for change
Signs of strain are already visible. In the last six months, 29% of HR leaders say the standard probation period no longer feels long enough for both sides to understand whether a hire is a good fit, and 28% say candidates overstated their capability at the application stage - evidence of a widening gap between how candidates present themselves and how they perform.
Looking ahead, 43% of employers expect probation periods to become even longer over the next 12 months. The main reasons include wanting to improve performance management and measurement (25%) and the increasing complexity of roles requiring deeper training and longer evaluation (21%).
Today, over half (52%) say probation periods within their company typically lasts two to three months, but within a year nearly half (44%) expect this to extend to four to six months, signalling the emergence of a new norm for the UK labour market.
