UK sales on a like-for-like basis, which strips out the impact of new stores, were up 3.7% in the three months to 23 September, reports the BBC.
However, sales in the Republic of Ireland fell by 2.1%.
Total sales for the group rose 7.9% to £136.4M. Domino's said e-commerce sales had continued to rise and now accounted for 58% of all its UK deliveries.
Total online sales in the quarter rose by 39.3% to £62.8M and orders from mobile phones accounted for nearly a fifth of online sales.
By 23 September, Domino's had 748 stores in the UK and Republic of Ireland and 10 in Germany.
The company recently completed the purchase of Domino's Switzerland, adding a further 12 stores to the group and giving it the rights to develop the market in Switzerland, Liechtenstein and Luxembourg.