select entry in Code column to view full DE allocations in that range
| Code | DEF | Operator | Use | Notes |
| 1600 | Monmouth | |||
| 1601, 1602 | Geographic - unassigned | |||
| 1603 | Norwich | |||
| 1604 | Northampton | |||
| 1605 | Geographic - unassigned | |||
| 1606 | Northwich | |||
| 1607 | Geographic - unassigned | |||
| 1608 | Chipping Norton | |||
| 1609 | Northallerton | |||
| 1610, 1611 | Manchester National dialling | |||
| 1612, 1613, 1614 | Manchester | |||
| 1615 | Manchester expansion | |||
| 1616, 1617, 1618, 1619 | Manchester | |||
| 1620 | North Berwick | |||
| 1621 | Maldon | |||
| 1622 | Maidstone | |||
| 1623 | Mansfield | |||
| 1624 | Isle of Man | |||
| 1625 | Macclesfield | |||
| 1626 | Newton Abbot | |||
| 1627 | Geographic - unassigned | |||
| 1628 | Maidenhead | |||
| 1629 | Matlock | |||
| 1630 | Market Drayton | |||
| 1631 | Oban | |||
| 1632 | Geographic - unassigned | |||
| 1633 | Newport | |||
| 1634 | Medway | |||
| 1635 | Newbury | |||
| 1636 | Newark | |||
| 1637 | Newquay | |||
| 1638 | Newmarket | |||
| 1639 | Neath | |||
| 1640 | Geographic - unassigned | |||
| 1641 | Strathy | |||
| 1642 | Middlesbrough | |||
| 1643 | Minehead | |||
| 1644 | New Galloway | |||
| 1645 | Geographic - unassigned | |||
| 1646 | Milford Haven | |||
| 1647 | Moretonhampstead | |||
| 1648 | Geographic - unassigned (formerly Magherafelt/Cookstown (Mixed 4/5 Digit Code Area)) | |||
| 1649 | Geographic - unassigned | |||
| 1650 | Cemmaes Road | |||
| 1651 | Oldmeldrum | |||
| 1652 | Brigg | |||
| 1653 | Malton | |||
| 1654 | Machynlleth | |||
| 1655 | Maybole | |||
| 1656 | Bridgend | |||
| 1657, 1658 | Geographic - unassigned | |||
| 1659 | Sanquhar | |||
| 1660 | Geographic - unassigned | |||
| 1661 | Prudhoe | |||
| 1662 | Geographic - unassigned (formerly Omagh/Ballygawley/Newtown/Carrickmore (Mixed 4/5 Digit Code Area) | |||
| 1663 | New Mills | |||
| 1664 | Melton Mowbray | |||
| 1665 | Alnwick | |||
| 1666 | Malmesbury | |||
| 1667 | Nairn | |||
| 1668 | Bamburgh | |||
| 1669 | Rothbury | |||
| 1670 | Morpeth | |||
| 1671 | Newton Stewart | |||
| 1672 | Marlborough | |||
| 1673 | Market Rasen | |||
| 1674 | Montrose | |||
| 1675 | Coleshill | |||
| 1676 | Meriden | |||
| 1677 | Bedale | |||
| 1678 | Bala | |||
| 1679 | Geographic - unassigned | |||
| 1680 | Isle of Mull - Craignure | |||
| 1681 | Isle of Mull - Fionnphort | |||
| 1682 | Geographic - unassigned | |||
| 1683 | Moffat | |||
| 1684 | Malvern | |||
| 1685 | Merthyr Tydfil | |||
| 1686 | 0&1 | Newtown/Llanidloes National Dialling | ELNS | |
| 1686 | 2-4 | Llanidloes | ELNS | |
| 1686 | 5&6 | Newtown | ELNS | |
| 1686 | 7 | Llanidloes | ELNS | |
| 1686 | 8&9 | Newtown | ELNS | |
| 1687 | Mallaig | |||
| 1688 | Isle of Mull - Tobermory | |||
| 1689 | Orpington | |||
| 1690 | Betws-y-Coed | |||
| 1691 | Oswestry | |||
| 1692 | North Walsham | |||
| 1693 | Geographic - unassigned (formerly Newry/Rostrevor (Mixed 4/5 Digit Code Area) | |||
| 1694 | Church Stretton | |||
| 1695 | Skelmersdale | |||
| 1696 | Geographic - unassigned | |||
| 1697 | 0-2 | Not in Use | ||
| 1697 | 3 | Wigton | 5 Digit Code Area | |
| 1697 | 4 | Raughton Head | 5 Digit Code Area | |
| 1697 | 5&6 | Not in Use | ||
| 1697 | 7 | Brampton | 4 Digit Code Area | |
| 1697 | 8 | Not in Use | ||
| 1697 | 9 | Brampton | ||
| 1698 | Motherwell | |||
| 1699 | Geographic - unassigned |