NTv2Poly is a new geospatial software for inserting area boundaries as Polygonal Validity Scopes in NTv2 files. With the geospatial software NTv2Poly by KilletSoft the rectangular activity scopes of NTv2 files can be replaced by Polygonal Validity Scopes which are defined as area boundaries in classic shape files. The NTv2 (National Transformation Version 2) file standard was developed by the "Department of Natural Resources of Canada" in the middle nineties. Using NTv2 grid files it is possible to transform geodata from one coordinate reference system to another with very high accuracy. An NTv2 file contains one or more quasi-rectangular grids with shift values. Instead of a rectangular area only an embedded polygonal area should and must be covered, for example, a state territory within the country borders. This article describes how Polygonal Validity Scopes can be realized in NTv2 files using a new developed software. The program NTv2Poly developed by KilletSoft realizes Polygonal Validity Scopes in NTv2 files. Using so prepared NTv2 files, coordinates outside the validity scope can be excluded from calculations or they can be acknowledged by a warning. This works with coordinate transformations using the geospatial software TRANSDAT and GeoDLL by KilletSoft and with GIS programs which support Polygonal Validity Scopes. The Polygonal Validity Scope is realized with a shape file, which contains the outlines of the scope as polygons. The file format Shape is developed by ESRI as a format for geographical objects. For example, in the shape file the border outlines of a country may be stored, which represent the polygonal scope for the NTv2 file used in that country. The polygons contained therein must be available as geographic coordinates in decimal notation. The reference system of the outline coordinates must correspond as closely as possible to the source reference system of the NTv2 file. A shape file in a different coordinate reference system can be converted into the required system using the geospatial software TRANSDAT by KilletSoft. Using the program NTv2Poly the polygons of the shape file and the quasi rectangular surface of the NTv2 file are superimposed one on the other and processed in an ingenious manner.