diff --git a/paths/customer_basic.yaml b/paths/customer_basic.yaml
index cf91a8b..3162a08 100644
--- a/paths/customer_basic.yaml
+++ b/paths/customer_basic.yaml
@@ -1,12 +1,14 @@
 get:
-  operationId: customerBasic
+  operationId: customerBasicGet
   tags:
     - Customer management
   summary: Basic info
   parameters:
     - name: agb
       in: query
-      description: AGB of the practice which is known as Zorg op Orde customer (via a care group).
+      description: |-
+        AGB of the practice for which basic info is requested.
+        If the requesting entity is a single GP practice, this parameter can be omitted.
       schema:
         $ref: ../schemas/agb.yaml
   responses:
@@ -33,7 +35,7 @@ get:
                   gpis:
                     $ref: ../schemas/GPIS.yaml
                   doctors:
-                    description: AGB's of the doctors working in the practice.
+                    description: AGBs of the doctors working in the practice.
                     type: array
                     items:
                       $ref: '../schemas/PatIdentity.yaml#/doctor'
@@ -81,4 +83,46 @@ get:
     '401':
       $ref: '../zoo-api.yaml/#/components/responses/NoAuth'
     '403':
-      $ref: '../zoo-api.yaml/#/components/responses/NoAccess'
\ No newline at end of file
+      $ref: '../zoo-api.yaml/#/components/responses/NoAccess'
+post:
+  operationId: customerBasicPost
+  tags:
+    - Customer management
+  summary: Basic info
+  description: Only certain properties of a practice can be updated. After updating the same response is outputted as when using GET.
+  parameters:
+    - name: agb
+      in: query
+      description: |-
+        AGB of the practice for which basic info is requested.
+        If the requesting entity is a single GP practice, this parameter can be omitted.
+      schema:
+        $ref: ../schemas/agb.yaml
+  requestBody:
+    description: |-
+      When authorized as a practice the address and contact data can be changed.
+      Currently, if authorized as a care group, no properties can be changed.
+      
+      Properties can be omitted if you do not want to change them. `address1` and `postcode` cannot be set to empty.
+    content:
+      'application/x-www-form-urlencoded':
+        schema:
+          type: object
+          properties:
+            address1:
+              type: string
+              description: The first line of the practice postal address (street name and house number, generally).
+            postcode:
+              description: Any valid Dutch postcode, with or without whitespacing and in lower- or uppercase.
+              $ref: ../schemas/postcode.yaml
+            city:
+              $ref: ../schemas/city.yaml
+            tel:
+              description: A Dutch phone number of 10 digits. Additional dashes and spacing are removed before validating.
+              type: string
+            email:
+              type: string
+              format: email
+  responses: 
+    $ref: '#/get/responses'
+    
\ No newline at end of file
diff --git a/schemas/GPIS.yaml b/schemas/GPIS.yaml
index 9d9095d..d8629e5 100644
--- a/schemas/GPIS.yaml
+++ b/schemas/GPIS.yaml
@@ -3,9 +3,7 @@ description: |-
 type: object
 properties:
   gpisType:
-    description: The type of GP Information System
-    type: string
-    example: Tetrapod
+    $ref: gpisType.yaml
   timestamp:
     description: |-
       The report is based on dossier data as it was on this timestamp; due to inaccuracies by GP information systems that source the data,
diff --git a/schemas/gpisType.yaml b/schemas/gpisType.yaml
new file mode 100644
index 0000000..c90eed6
--- /dev/null
+++ b/schemas/gpisType.yaml
@@ -0,0 +1,13 @@
+type: string
+description: |-
+  Type brand (or type) of the general practitioner information system (EDP). Query the `/customer/gpisType` end point for a list of all brands.
+enum:
+  - healthconnected
+  - medicom
+  - scipio
+  - microhis
+  - promedico
+  - tetra
+  - sanday
+  - microhis
+  - medikit