select entry in Code column to view full DE allocations in that range
| Code | DEF | Operator | Use | Notes |
| 2800, 2801, 2802, 2803, 2804, 2805, 2806, 2807, 2808, 2809 | 028 National Dialling expansion | |||
| 2810, 2811 | Nothern Ireland National Dialling | |||
| 2812, 2813, 2814, 2815, 2816, 2817, 2818, 2819 | 028 National Dialling expansion | |||
| 2820 | Ballycastle | |||
| 2821 | Martinstown | |||
| 2822, 2823, 2824 | 028 Geographic expansion | |||
| 2825 | Ballymena | |||
| 2826 | 028 Geographic expansion | |||
| 2827 | Ballymoney | |||
| 2828 | Larne | |||
| 2829 | Kilrea | |||
| 2830 | Newry | |||
| 2831, 2832, 2833, 2834, 2835, 2836 | 028 Geographic expansion | |||
| 2837 | Armagh | |||
| 2838 | Portadown | |||
| 2839 | 028 Geographic expansion | |||
| 2840 | Banbridge | |||
| 2841 | Rostrevor | |||
| 2842 | Kircubbin | |||
| 2843 | Newcastle | |||
| 2844 | Downpatrick | |||
| 2845, 2846, 2847, 2848, 2849, 2850, 2851, 2852, 2853, 2854, 2855, 2856, 2857, 2858, 2859, 2860, 2861, 2862, 2863, 2864, 2865 | 028 Geographic expansion | |||
| 2866 | Enniskillen | |||
| 2867 | Lisnaskea | |||
| 2868 | Kesh | |||
| 2869 | 028 Geographic expansion | |||
| 2870 | Coleraine | |||
| 2871 | Londonderry | |||
| 2872, 2873, 2874, 2875, 2876 | 028 Geographic expansion | |||
| 2877 | Limavady | |||
| 2878 | 028 Geographic expansion | |||
| 2879 | Magherafelt | |||
| 2880 | Carrickmore | |||
| 2881 | Newtownstewart | |||
| 2882 | Omagh | |||
| 2883, 2884 | 028 Geographic expansion | |||
| 2885 | Ballygawley | |||
| 2886 | Cookstown | |||
| 2887 | Dungannon | |||
| 2888 | 028 Geographic expansion | |||
| 2889 | Fivemiletown | |||
| 2890 | Belfast City | |||
| 2891 | Bangor | |||
| 2892 | Lisburn | |||
| 2893 | Ballyclare | |||
| 2894 | Antrim | |||
| 2895 | Belfast | |||
| 2896 | Belfast expansion | |||
| 2897 | Saintfield | |||
| 2898 | Belfast expansion | |||
| 2899 | Northern Ireland Emergency Services |