Do you have a plastic bag?
BU-sta — the 'u' is rounded and short; 'pla-STI-ca' — stress on the second syllable.
Use this after making several purchases when you need a bag to carry them. Note that since 2011 Italy has banned non-biodegradable plastic bags, so bags may be paper or biodegradable plastic.
'Ha una busta' uses the formal 'ha'. Since Italian legislation mandated biodegradable bags, many shops now offer only paper bags (busta di carta) or charge a small fee for bags. In tabaccherie, bags are sometimes provided free with larger purchases.
Ha una busta di carta?
Do you have a paper bag?
More common now in Italy due to plastic bag regulations
Può mettermi tutto in un sacchetto?
Can you put everything in a bag for me?
'Sacchetto' (small bag) is also very common
Quanto costa la busta?
How much does the bag cost?
Bags may cost €0.10–0.20 — always worth asking
Italy was one of the first countries in Europe to ban traditional plastic bags (sacchetti di plastica). Since 2011, only bags made of biodegradable or compostable materials are legal. Reusable bags (borse riutilizzabili) are commonly available for purchase at tabaccherie.