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HMRC internal manual

PAYE Manual

Coding: codes: how they are used and calculated: suffix codes: calculating the number

A suffix code is made up of a number followed by a suffix letter. The number comes fromthe net coding allowances. The general rule is to take the net coding allowances and dropthe final digit.

The table below shows how it works.

Net coding allowances Number used in code
1 - 19 1
20 - 29 2
270 - 279 27
2700 - 2709 270
2740 - 2749 274

You can see from the table that there is one exception to the general rule. For net codingallowances between 1 and 9 do not use 0 – use the number 1 instead.