ArcMap - How to Format Data for Import

For Data Values (numbers, percentages, etc.)

1. Be sure that there are no spaces before or after your values.  ArcMap tries to read these as part of the value field.
2. All null/empty fields must be converted to 0. 
3. ID numbers must be in General format - no numbers or text
   1. If your numbers are formatted as General, but are left justified, Excel is storing them as text.  These will not import properly into ArcGIS.  To fix this problem, do the following:
      1. In an empty cell of the spreadsheet, type the number 1
      2. Copy the cell with the number 1 you just created
      3. Highlight all of the General cells with text formatting - they will be left justified.
      4. Go to the Home tab, click on the black arrow underneath the Paste button and choose Paste Special.  The Paste Special dialog box will appear.
      5. In the Paste Special dialog box under the Paste options, choose Values.  Under the Operations options choose Multiply.
      6. Click OK.
   2. If your numbers are right justified and the cells are formatted as General, they should be able to  be used properly as ID numbers in ArcGIS
4. make sure all values for quantities are formatted as numbers.  You must preserve leading zeros.
5. if error message for number stored as text, change so that this error message no longer occurs.
6. Everything formatted as general shows up in ArcCatalog as Double

For Addresses (Geocoding)

1. Be sure that there are no spaces before or after the end of your address, city, zip code, or other letter and number strings.  ArcMap tries to read these as part of the name, etc..
2. Make sure that addresses are split into different fields for street address, city, and postal code. 
3. Street addresses should have no periods in them, even for abbreviated terms like Ave, W, E, or St.
4. Use common abbreviations like Ave, W or St.  You may also spell the words out, ie: Lane or Circle.
5. Double check the spelling for streets and cities. Be sure that your spelling and abbreviations match exactly the official street name.  Is it "Mount Carmel Ave" or "Mt Carmel Ave?"  Database entries are matched exactly, so your entries for upload should match as exactly as possible.

If there are mistakes in your data for geocoding, there are ways to rectify them.  See the tutorial information on reconciling unmatched and tied addresses for help.