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<jats:title>Purpose</jats:title>
<jats:p>The digital transformation of public administration has positioned citizen satisfaction and loyalty as critical indicators for evaluating the effectiveness of digital services. This study aims to examine user perceptions of the Portuguese Tax Authority’s (Autoridade Tributária – AT) digital platforms, including the Portal das Finanças and mobile applications.</jats:p>
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<jats:title>Design/methodology/approach</jats:title>
<jats:p>Based on a sample of 372 valid responses collected during the COVID-19 pandemic, the research applies descriptive and inferential statistical analyses, including t-tests, Spearman’s correlations and Kruskal-Wallis tests.</jats:p>
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<jats:title>Findings</jats:title>
<jats:p>The results indicate moderate to high levels of citizen satisfaction, with trust, ease of use and perceived service quality emerging as the primary drivers. No significant differences in satisfaction or loyalty were found based on gender, education level or user type (individual taxpayer vs. professional user). However, age, duration of use and frequency of use were identified as significant factors influencing satisfaction and loyalty.</jats:p>
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<jats:title>Originality/value</jats:title>
<jats:p>The study extends the application of service quality models to the digital fiscal services domain and offers practical insights for enhancing citizen engagement, fostering trust and sustaining digital transformation in public administration. By highlighting the behavioural dynamics underpinning citizen loyalty in fiscal e-government services, the research contributes to the broader discourse on public sector innovation and citizen relationship management.</jats:p>
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