Looking up and displaying new entries in a column

[aprabhat]

I have list of customers per month in column. I'm trying extract the new customers each month, ignoring customers that have already been listed in past months, then display them in a table below. File is attached.
This is the formula I'm using

IF(P38=0,0,IF(ISNA(MATCH(P38,$K$10:O$47,0)),P38,0))

However, it seems like the match function I'm using ends up displaying even repeat customers (example Customer00038 which is already in Nov 2019 and repeats in Jan 2020)

test.xlsx
	I	J	K	L	M	N	O	P	Q	R
3	ALL CUSTOMERS		Aug-2019	Sep-2019	Oct-2019	Nov-2019	Dec-2019	Jan-2020	Feb-2020	Mar-2020
4			Customer00001	Customer00006	Customer00017	Customer00028	Customer00048	Customer00077	Customer00104	Customer00140
5			Customer00002	Customer00007	Customer00018	Customer00029	Customer00049	Customer00078	Customer00105	Customer00141
6			Customer00003	Customer00008	Customer00019	Customer00030	Customer00050	Customer00079	Customer00106	Customer00142
7			Customer00004	Customer00009	Customer00020	Customer00031	Customer00051	Customer00080	Customer00107	Customer00103
8			Customer00005	Customer00010	Customer00021	Customer00032	Customer00052	Customer00081	Customer00108	Customer00143
9				Customer00011	Customer00022	Customer00033	Customer00053	Customer00082	Customer00109	Customer00144
10				Customer00012	Customer00023	Customer00034	Customer00054	Customer00083	Customer00110	Customer00145
11				Customer00013	Customer00024	Customer00001	Customer00055	Customer00084	Customer00111	Customer00146
12				Customer00014	Customer00025	Customer00035	Customer00056	Customer00085	Customer00112	Customer00147
13				Customer00015	Customer00026	Customer00036	Customer00057	Customer00086	Customer00113	Customer00148
14				Customer00016	Customer00027	Customer00037	Customer00058	Customer00087	Customer00114	Customer00149
15						Customer00038	Customer00059	Customer00088	Customer00115	Customer00150
16						Customer00039	Customer00060	Customer00089	Customer00116	Customer00151
17						Customer00040	Customer00061	Customer00090	Customer00117	Customer00152
18						Customer00041	Customer00062	Customer00091	Customer00118	Customer00153
19						Customer00042	Customer00063	Customer00092	Customer00119	Customer00154
20						Customer00043	Customer00064	Customer00093	Customer00120	Customer00155
21						Customer00044	Customer00065	Customer00094	Customer00121	Customer00156
22						Customer00045	Customer00066	Customer00095	Customer00122	Customer00157
23						Customer00046	Customer00067	Customer00096	Customer00123	Customer00158
24						Customer00047	Customer00068	Customer00097	Customer00124	Customer00159
25							Customer00069	Customer00098	Customer00125	Customer00160
26							Customer00070	Customer00099	Customer00126	Customer00161
27							Customer00071	Customer00100	Customer00089	Customer00162
28							Customer00072	Customer00101	Customer00127	Customer00163
29							Customer00073	Customer00102	Customer00128	Customer00164
30							Customer00074	Customer00103	Customer00129	Customer00165
31							Customer00075	Customer00038	Customer00130	Customer00166
32							Customer00076		Customer00131	Customer00167
33									Customer00132	Customer00168
34									Customer00133
35									Customer00134
36									Customer00135
37									Customer00136
38									Customer00137
39									Customer00138
40									Customer00139
41
42	NEW CUSTOMERS		Aug-2019	Sep-2019	Oct-2019	Nov-2019	Dec-2019	Jan-2020	Feb-2020	Mar-2020
43			Customer00001	Customer00006	Customer00017	Customer00028	Customer00048	Customer00077	Customer00104	Customer00140
44			Customer00002	Customer00007	Customer00018	Customer00029	Customer00049	Customer00078	Customer00105	Customer00141
45			Customer00003	Customer00008	Customer00019	Customer00030	Customer00050	Customer00079	Customer00106	Customer00142
46			Customer00004	Customer00009	Customer00020	Customer00031	Customer00051	Customer00080	Customer00107	Customer00103
47			Customer00005	Customer00010	Customer00021	Customer00032	Customer00052	Customer00081	Customer00108	Customer00143
48			0	Customer00011	Customer00022	Customer00033	Customer00053	Customer00082	Customer00109	Customer00144
49			0	Customer00012	Customer00023	Customer00034	Customer00054	Customer00083	Customer00110	Customer00145
50			0	Customer00013	Customer00024	Customer00001	Customer00055	Customer00084	Customer00111	Customer00146
51			0	Customer00014	Customer00025	Customer00035	Customer00056	Customer00085	Customer00112	Customer00147
52			0	Customer00015	Customer00026	Customer00036	Customer00057	Customer00086	Customer00113	Customer00148
53			0	Customer00016	Customer00027	Customer00037	Customer00058	Customer00087	Customer00114	Customer00149
54			0	0	0	Customer00038	Customer00059	Customer00088	Customer00115	Customer00150
55			0	0	0	Customer00039	Customer00060	Customer00089	Customer00116	Customer00151
56			0	0	0	Customer00040	Customer00061	Customer00090	Customer00117	Customer00152
57			0	0	0	Customer00041	Customer00062	Customer00091	Customer00118	Customer00153
58			0	0	0	Customer00042	Customer00063	Customer00092	Customer00119	Customer00154
59			0	0	0	Customer00043	Customer00064	Customer00093	Customer00120	Customer00155
60			0	0	0	Customer00044	Customer00065	Customer00094	Customer00121	Customer00156
61			0	0	0	Customer00045	Customer00066	Customer00095	Customer00122	Customer00157
62			0	0	0	Customer00046	Customer00067	Customer00096	Customer00123	Customer00158
63			0	0	0	Customer00047	Customer00068	Customer00097	Customer00124	Customer00159
64			0	0	0	0	Customer00069	Customer00098	Customer00125	Customer00160
65			0	0	0	0	Customer00070	Customer00099	Customer00126	Customer00161
66			0	0	0	0	Customer00071	Customer00100	Customer00089	Customer00162
67			0	0	0	0	Customer00072	Customer00101	Customer00127	Customer00163
68			0	0	0	0	Customer00073	Customer00102	Customer00128	Customer00164
69			0	0	0	0	Customer00074	Customer00103	Customer00129	Customer00165
70			0	0	0	0	Customer00075	Customer00038	Customer00130	Customer00166
71			0	0	0	0	Customer00076	0	Customer00131	Customer00167
72			0	0	0	0	0	0	Customer00132	Customer00168
73			0	0	0	0	0	0	Customer00133	0
74			0	0	0	0	0	0	Customer00134	0
75			0	0	0	0	0	0	Customer00135	0
76			0	0	0	0	0	0	Customer00136	0
77			0	0	0	0	0	0	Customer00137	0
78			0	0	0	0	0	0	Customer00138	0
79			0	0	0	0	0	0	Customer00139	0
Sheet1

Cell Formulas
Range	Formula
K43:K79	K43	=IF(K4=0,0,IF(ISNA(MATCH(K4,J$4:$K$40,0)),K4,0))
L43:R79	L43	=IF(L4=0,0,IF(ISNA(MATCH(L4,$K$4:K$40,0)),L4,0))

 

[Fluff]

Match only takes a 1D array, but you are trying to use a 2D array.
Try

+Fluff 1.xlsm
	I	J	K	L	M	N	O	P	Q	R
1
2
3	ALL CUSTOMERS		Aug-19	Sep-19	Oct-19	Nov-19	Dec-19	Jan-20	Feb-20	Mar-20
4			Customer00001	Customer00006	Customer00017	Customer00028	Customer00048	Customer00077	Customer00104	Customer00140
5			Customer00002	Customer00007	Customer00018	Customer00029	Customer00049	Customer00078	Customer00105	Customer00141
6			Customer00003	Customer00008	Customer00019	Customer00030	Customer00050	Customer00079	Customer00106	Customer00142
7			Customer00004	Customer00009	Customer00020	Customer00031	Customer00051	Customer00080	Customer00107	Customer00103
8			Customer00005	Customer00010	Customer00021	Customer00032	Customer00052	Customer00081	Customer00108	Customer00143
9				Customer00011	Customer00022	Customer00033	Customer00053	Customer00082	Customer00109	Customer00144
10				Customer00012	Customer00023	Customer00034	Customer00054	Customer00083	Customer00110	Customer00145
11				Customer00013	Customer00024	Customer00001	Customer00055	Customer00084	Customer00111	Customer00146
12				Customer00014	Customer00025	Customer00035	Customer00056	Customer00085	Customer00112	Customer00147
13				Customer00015	Customer00026	Customer00036	Customer00057	Customer00086	Customer00113	Customer00148
14				Customer00016	Customer00027	Customer00037	Customer00058	Customer00087	Customer00114	Customer00149
15						Customer00038	Customer00059	Customer00088	Customer00115	Customer00150
16						Customer00039	Customer00060	Customer00089	Customer00116	Customer00151
17						Customer00040	Customer00061	Customer00090	Customer00117	Customer00152
18						Customer00041	Customer00062	Customer00091	Customer00118	Customer00153
19						Customer00042	Customer00063	Customer00092	Customer00119	Customer00154
20						Customer00043	Customer00064	Customer00093	Customer00120	Customer00155
21						Customer00044	Customer00065	Customer00094	Customer00121	Customer00156
22						Customer00045	Customer00066	Customer00095	Customer00122	Customer00157
23						Customer00046	Customer00067	Customer00096	Customer00123	Customer00158
24						Customer00047	Customer00068	Customer00097	Customer00124	Customer00159
25							Customer00069	Customer00098	Customer00125	Customer00160
26							Customer00070	Customer00099	Customer00126	Customer00161
27							Customer00071	Customer00100	Customer00089	Customer00162
28							Customer00072	Customer00101	Customer00127	Customer00163
29							Customer00073	Customer00102	Customer00128	Customer00164
30							Customer00074	Customer00103	Customer00129	Customer00165
31							Customer00075	Customer00038	Customer00130	Customer00166
32							Customer00076		Customer00131	Customer00167
33									Customer00132	Customer00168
34									Customer00133
35									Customer00134
36									Customer00135
37									Customer00136
38									Customer00137
39									Customer00138
40									Customer00139
41
42	NEW CUSTOMERS		Aug-19	Sep-19	Oct-19	Nov-19	Dec-19	Jan-20	Feb-20	Mar-20
43			Customer00001	Customer00006	Customer00017	Customer00028	Customer00048	Customer00077	Customer00104	Customer00140
44			Customer00002	Customer00007	Customer00018	Customer00029	Customer00049	Customer00078	Customer00105	Customer00141
45			Customer00003	Customer00008	Customer00019	Customer00030	Customer00050	Customer00079	Customer00106	Customer00142
46			Customer00004	Customer00009	Customer00020	Customer00031	Customer00051	Customer00080	Customer00107	Customer00143
47			Customer00005	Customer00010	Customer00021	Customer00032	Customer00052	Customer00081	Customer00108	Customer00144
48				Customer00011	Customer00022	Customer00033	Customer00053	Customer00082	Customer00109	Customer00145
49				Customer00012	Customer00023	Customer00034	Customer00054	Customer00083	Customer00110	Customer00146
50				Customer00013	Customer00024	Customer00035	Customer00055	Customer00084	Customer00111	Customer00147
51				Customer00014	Customer00025	Customer00036	Customer00056	Customer00085	Customer00112	Customer00148
52				Customer00015	Customer00026	Customer00037	Customer00057	Customer00086	Customer00113	Customer00149
53				Customer00016	Customer00027	Customer00038	Customer00058	Customer00087	Customer00114	Customer00150
54						Customer00039	Customer00059	Customer00088	Customer00115	Customer00151
55						Customer00040	Customer00060	Customer00089	Customer00116	Customer00152
56						Customer00041	Customer00061	Customer00090	Customer00117	Customer00153
57						Customer00042	Customer00062	Customer00091	Customer00118	Customer00154
58						Customer00043	Customer00063	Customer00092	Customer00119	Customer00155
59						Customer00044	Customer00064	Customer00093	Customer00120	Customer00156
60						Customer00045	Customer00065	Customer00094	Customer00121	Customer00157
61						Customer00046	Customer00066	Customer00095	Customer00122	Customer00158
62						Customer00047	Customer00067	Customer00096	Customer00123	Customer00159
63							Customer00068	Customer00097	Customer00124	Customer00160
64							Customer00069	Customer00098	Customer00125	Customer00161
65							Customer00070	Customer00099	Customer00126	Customer00162
66							Customer00071	Customer00100	Customer00127	Customer00163
67							Customer00072	Customer00101	Customer00128	Customer00164
68							Customer00073	Customer00102	Customer00129	Customer00165
69							Customer00074	Customer00103	Customer00130	Customer00166
70							Customer00075		Customer00131	Customer00167
71							Customer00076		Customer00132	Customer00168
72									Customer00133
73									Customer00134
74									Customer00135
75									Customer00136
76									Customer00137
77									Customer00138
78									Customer00139
79
80
Lists

Cell Formulas
Range	Formula
K43:K47	K43	=FILTER(K4:K40,K4:K40<>"")
L43:L53	L43	=FILTER(L4:L40,(L4:L40<>"")*(COUNTIF(K43#,L4:L40)=0))
M43:M53,R43:R71,Q43:Q78,P43:P69,O43:O71,N43:N62	M43	=FILTER(M4:M40,(M4:M40<>"")*(COUNTIF($K43#:L43#,M4:M40)=0))
Dynamic array formulas.

 

[aprabhat]

Thanks! That worked

 

[Fluff]

You're welcome & thanks for the feedback.