This experimental study aims to investigate the effect of nudges and prize-linked savings (PLS) accounts and examine the external validity of laboratory experiments on savings behaviour. We employ a natural setting for our experiment in collaboration with a professional survey company operating in Latvia and Estonia. The company on a daily basis recruits respondents to take part in commissioned surveys in return for payment. While usually, the payment to the respondents takes place immediately after filling out a survey, the experimental design presented participants with a choice between immediate and delayed consumption of the money earned. The experimental design consisted of three experimental groups. In the baseline offer, respondents were given a choice between receiving 10 euros immediately or depositing all or part of the amount in a virtual savings account for six months, with a maximum payout of 12 euros. In the social norm treatment, respondents were informed before the choice question that the survey focuses on household financial behaviour and that previous surveys revealed that the majority of respondents choose to save. The PLS account treatment offered individuals, who allocated all 10 euros to the savings account, to participate in a lottery with the chance to win an additional 5 euros on top of the interest earned. The experimental results show that both social norm nudge and PLS account treatments tend to increase the number of individuals who decide to save. However, the effect is significantly smaller than the one found in laboratory experiments that have examined the effect of PLS accounts on savings behaviour. We also identify several suggestive savings patterns that are in line with previous studies and support the external validity of this study. First, individuals who play lotteries are more likely to invest in PLS, while non-lottery players are more responsive to social norms. Second, Estonians tend to save more often than Latvians, a trend that has been found in many empirical studies. Taken together, the results of this field experiment provide a more accurate representation of the true behaviour of individuals when it comes to savings and investment decisions. It also suggests that social norms can be as persuasive as financial incentives to increase the savings level.