diff --git a/client/src/views/fields/address.js b/client/src/views/fields/address.js
index 44ebf580fb..3f9b13d145 100644
--- a/client/src/views/fields/address.js
+++ b/client/src/views/fields/address.js
@@ -58,7 +58,10 @@ class AddressFieldView extends BaseFieldView {
     stateField
     countryField
 
-    /** @inheritDoc */
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
     validations = [
         'required',
         'pattern',
diff --git a/client/src/views/fields/array.js b/client/src/views/fields/array.js
index ff19338bbc..7bc8c87068 100644
--- a/client/src/views/fields/array.js
+++ b/client/src/views/fields/array.js
@@ -87,7 +87,13 @@ class ArrayFieldView extends BaseFieldView {
 
     searchTypeList = ['anyOf', 'noneOf', 'allOf', 'isEmpty', 'isNotEmpty']
     maxItemLength = null
+
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
     validations = ['required', 'maxCount']
+
     MAX_ITEM_LENGTH = 100
 
     /**
diff --git a/client/src/views/fields/attachment-multiple.js b/client/src/views/fields/attachment-multiple.js
index 388ec921a9..13a6174378 100644
--- a/client/src/views/fields/attachment-multiple.js
+++ b/client/src/views/fields/attachment-multiple.js
@@ -82,11 +82,17 @@ class AttachmentMultipleFieldView extends BaseFieldView {
     foreignScope
     showPreviews = true
     accept = null
+
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
     validations = [
         'ready',
         'required',
         'maxCount',
     ]
+
     searchTypeList = ['isNotEmpty', 'isEmpty']
 
     events = {
diff --git a/client/src/views/fields/base.js b/client/src/views/fields/base.js
index 498c7100d2..b937694847 100644
--- a/client/src/views/fields/base.js
+++ b/client/src/views/fields/base.js
@@ -137,9 +137,12 @@ class BaseFieldView extends View {
     editTemplateContent
 
     /**
-     * A validation list. There should be a `validate{Name}` method for each item.
+     * A validation list. A function returning true if non-valid, or a name.
+     * For the latter, there should be a `validate{Name}` method in the class.
      *
-     * @type {string[]}
+     * Functions are supported as of v8.4.
+     *
+     * @type {Array<(function (): boolean)|string>}
      */
     validations = ['required']
 
@@ -1542,10 +1545,18 @@ class BaseFieldView extends View {
     validate() {
         this.lastValidationMessage = null;
 
-        for (const i in this.validations) {
-            const method = 'validate' + Espo.Utils.upperCaseFirst(this.validations[i]);
+        for (const item of this.validations) {
+            let notValid = false;
 
-            if (this[method].call(this)) {
+            if (typeof item === 'function') {
+                notValid = item();
+            } else {
+                const method = 'validate' + Espo.Utils.upperCaseFirst(item);
+
+                notValid = this[method].call(this);
+            }
+
+            if (notValid) {
                 this.trigger('invalid');
 
                 return true;
diff --git a/client/src/views/fields/currency.js b/client/src/views/fields/currency.js
index 9d1061d37a..feaf88f96d 100644
--- a/client/src/views/fields/currency.js
+++ b/client/src/views/fields/currency.js
@@ -90,6 +90,10 @@ class CurrencyFieldView extends FloatFieldView {
 
     maxDecimalPlaces = 3
 
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
     validations = [
         'required',
         'number',
diff --git a/client/src/views/fields/date.js b/client/src/views/fields/date.js
index 4cc8d24c9a..ee6bbc2d21 100644
--- a/client/src/views/fields/date.js
+++ b/client/src/views/fields/date.js
@@ -71,6 +71,10 @@ class DateFieldView extends BaseFieldView {
     editTemplate = 'fields/date/edit'
     searchTemplate = 'fields/date/search'
 
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
     validations = [
         'required',
         'date',
diff --git a/client/src/views/fields/datetime.js b/client/src/views/fields/datetime.js
index 18d1124292..e663e32926 100644
--- a/client/src/views/fields/datetime.js
+++ b/client/src/views/fields/datetime.js
@@ -69,7 +69,16 @@ class DatetimeFieldView extends DateFieldView {
 
     editTemplate = 'fields/datetime/edit'
 
-    validations = ['required', 'datetime', 'after', 'before']
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
+    validations = [
+        'required',
+        'datetime',
+        'after',
+        'before',
+    ]
 
     searchTypeList = [
         'lastSevenDays',
diff --git a/client/src/views/fields/float.js b/client/src/views/fields/float.js
index ae789582ae..d7e8f62ad2 100644
--- a/client/src/views/fields/float.js
+++ b/client/src/views/fields/float.js
@@ -70,9 +70,14 @@ class FloatFieldView extends IntFieldView {
     editTemplate = 'fields/float/edit'
 
     decimalMark = '.'
-    validations = ['required', 'float', 'range']
     decimalPlacesRawValue = 10
 
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
+    validations = ['required', 'float', 'range']
+
     /** @inheritDoc */
     setup() {
         super.setup();
diff --git a/client/src/views/fields/int.js b/client/src/views/fields/int.js
index c8e6132289..57dab59b4f 100644
--- a/client/src/views/fields/int.js
+++ b/client/src/views/fields/int.js
@@ -71,6 +71,11 @@ class IntFieldView extends BaseFieldView {
     detailTemplate = 'fields/int/detail'
     editTemplate = 'fields/int/edit'
     searchTemplate = 'fields/int/search'
+
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
     validations = ['required', 'int', 'range']
 
     thousandSeparator = ','
diff --git a/client/src/views/fields/link-multiple.js b/client/src/views/fields/link-multiple.js
index 6cbc09024f..2b0d1117ca 100644
--- a/client/src/views/fields/link-multiple.js
+++ b/client/src/views/fields/link-multiple.js
@@ -74,6 +74,10 @@ class LinkMultipleFieldView extends BaseFieldView {
     editTemplate = 'fields/link-multiple/edit'
     searchTemplate = 'fields/link-multiple/search'
 
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
     validations = [
         'required',
         'maxCount',
diff --git a/client/src/views/fields/url.js b/client/src/views/fields/url.js
index fb3dbdcb4a..31d1ee1476 100644
--- a/client/src/views/fields/url.js
+++ b/client/src/views/fields/url.js
@@ -70,6 +70,10 @@ class UrlFieldView extends VarcharFieldView {
     detailTemplate = 'fields/url/detail'
     defaultProtocol = 'https:'
 
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
     validations = [
         'required',
         'valid',
diff --git a/client/src/views/fields/varchar.js b/client/src/views/fields/varchar.js
index 9ed6da54e2..3d7b369d3e 100644
--- a/client/src/views/fields/varchar.js
+++ b/client/src/views/fields/varchar.js
@@ -88,7 +88,10 @@ class VarcharFieldView extends BaseFieldView {
         'isNotEmpty',
     ]
 
-    /** @inheritDoc */
+    /**
+     * @inheritDoc
+     * @type {Array<(function (): boolean)|string>}
+     */
     validations = [
         'required',
         'pattern',