diff --git a/hledger-lib/Hledger/Read/Common.hs b/hledger-lib/Hledger/Read/Common.hs
index b23a9c3e5..a3634aa73 100644
--- a/hledger-lib/Hledger/Read/Common.hs
+++ b/hledger-lib/Hledger/Read/Common.hs
@@ -1169,7 +1169,20 @@ rawnumberp = label "number" $ do
     pure $ NoSeparators grp1 (Just (decPt, mempty))
 
 isDigitSeparatorChar :: Char -> Bool
-isDigitSeparatorChar c = isDecimalMark c || c == ' '
+isDigitSeparatorChar c = isDecimalMark c || isDigitSeparatorSpaceChar c
+
+-- | Kinds of unicode space character we accept as digit group marks.
+-- See also https://en.wikipedia.org/wiki/Decimal_separator#Digit_grouping .
+isDigitSeparatorSpaceChar :: Char -> Bool
+isDigitSeparatorSpaceChar c =
+     c == ' '  -- space
+  || c == ' '  -- no-break space
+  || c == ' '  -- en space
+  || c == ' '  -- em space
+  || c == ' '  -- punctuation space
+  || c == ' '  -- thin space
+  || c == ' '  -- narrow no-break space
+  || c == ' '  -- medium mathematical space
 
 -- | Some kinds of number literal we might parse.
 data RawNumber
diff --git a/hledger/hledger.m4.md b/hledger/hledger.m4.md
index 50a6bd568..5637603c4 100644
--- a/hledger/hledger.m4.md
+++ b/hledger/hledger.m4.md
@@ -1200,13 +1200,23 @@ A *decimal mark* can be written as a period or a comma:
     1,23
 
 In the integer part of the quantity (left of the decimal mark), groups
-of digits can optionally be separated by a *digit group mark* - a
-space, comma, or period (different from the decimal mark):
+of digits can optionally be separated by a *digit group mark* -
+a comma or period (whichever is not used as decimal mark), 
+or a space (any of these Unicode space characters:
+space,
+no-break space,
+en space,
+em space,
+punctuation space,
+thin space,
+narrow no-break space,
+medium mathematical space).
 
          $1,000,000.00
       EUR 2.000.000,00
     INR 9,99,99,999.00
-          1 000 000.9455
+          1 000 000.00   <- ordinary space  
+          1 000 000.00   <- no-break space
 
 hledger is not biased towards [period or comma decimal marks][international number formats],
 so a number containing just one period or comma, like `1,000` or `1.000`, is ambiguous.
diff --git a/hledger/test/journal/numbers.test b/hledger/test/journal/numbers.test
index d9ab010dc..931f3e13d 100644
--- a/hledger/test/journal/numbers.test
+++ b/hledger/test/journal/numbers.test
@@ -36,14 +36,27 @@ $ hledger bal -f -
 >2 //
 >= 1
 
-# ** 5. Space between digits groups
+# ** 5. Spaces between digit groups, any of the 8 unicode space characters we support.
 <
-2017/1/1
-	a   1 000.00 EUR
-	b  -1 000.00 EUR
-$ hledger bal -f - --no-total
-        1 000.00 EUR  a
-       -1 000.00 EUR  b
+2000-01-01
+  (a)  1 000. A  ; space                    
+  (b)  1 000. B  ; no-break space           
+  (c)  1 000. C  ; en space                 
+  (d)  1 000. D  ; em space                 
+  (e)  1 000. E  ; punctuation space        
+  (f)  1 000. F  ; thin space               
+  (g)  1 000. G  ; narrow no-break space    
+  (h)  1 000. H  ; medium mathematical space
+
+$ hledger bal -f - -N
+             1 000 A  a
+             1 000 B  b
+             1 000 C  c
+             1 000 D  d
+             1 000 E  e
+             1 000 F  f
+             1 000 G  g
+             1 000 H  h
 
 # ** 6. Space between digits groups in commodity directive
 <
@@ -203,3 +216,24 @@ Balance changes in 2021:
 ===++===================================
  a || -0.12345678901234567890123456 EUR 
 
+# ** 21. When spaces are used inconsistently, what happens ? The usual, first one seen sets commodity style.
+<
+2000-01-01
+  (a)  1 000. A  ; no-break space           
+  (a)  1 000. A  ; space                    
+  (a)  1 000. A  ; en space                 
+
+$ hledger bal -f - -N
+             3 000 A  a
+
+# ** 22. And a commodity directive can enforce consistency as usual.
+<
+commodity 1 000. A  ; narrow no-break space
+
+2000-01-01
+  (a)  1 000. A  ; space                    
+  (a)  1 000. A  ; no-break space           
+  (a)  1 000. A  ; en space                 
+
+$ hledger bal -f - -N
+             3 000 A  a