diff --git a/apps/services/regulations-admin-backend/src/app/modules/draft_regulation/models/appendix.model.ts b/apps/services/regulations-admin-backend/src/app/modules/draft_regulation/models/appendix.model.ts
index 4cace51397c8..12fbbd5f8dcc 100644
--- a/apps/services/regulations-admin-backend/src/app/modules/draft_regulation/models/appendix.model.ts
+++ b/apps/services/regulations-admin-backend/src/app/modules/draft_regulation/models/appendix.model.ts
@@ -1,4 +1,4 @@
-import { ApiProperty } from '@nestjs/swagger'
+import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger'
 import { HTMLText, PlainText } from '@island.is/regulations'
 
 export class AppendixModel {
@@ -7,4 +7,7 @@ export class AppendixModel {
 
   @ApiProperty()
   text!: HTMLText
+
+  @ApiPropertyOptional()
+  diff?: HTMLText
 }
diff --git a/apps/services/regulations-admin-backend/src/main.ts b/apps/services/regulations-admin-backend/src/main.ts
index b0f1f43fea55..9be0492bcc5c 100644
--- a/apps/services/regulations-admin-backend/src/main.ts
+++ b/apps/services/regulations-admin-backend/src/main.ts
@@ -7,5 +7,5 @@ bootstrap({
   appModule: AppModule,
   name: 'regulations-admin-backend',
   openApi,
-  jsonBodyLimit: '300kb',
+  jsonBodyLimit: '400kb',
 })
diff --git a/libs/api/domains/regulations-admin/src/lib/graphql/dto/createDraftRegulationChange.input.ts b/libs/api/domains/regulations-admin/src/lib/graphql/dto/createDraftRegulationChange.input.ts
index b4ab9905c0ab..64af25d4dddd 100644
--- a/libs/api/domains/regulations-admin/src/lib/graphql/dto/createDraftRegulationChange.input.ts
+++ b/libs/api/domains/regulations-admin/src/lib/graphql/dto/createDraftRegulationChange.input.ts
@@ -8,6 +8,9 @@ class CreateChangeAppendixInput {
 
   @Field(() => String, { nullable: true })
   text!: HTMLText
+
+  @Field(() => String, { nullable: true })
+  diff?: HTMLText
 }
 @InputType()
 export class CreateDraftRegulationChangeInput {
diff --git a/libs/api/domains/regulations-admin/src/lib/graphql/dto/updateDraftRegulationChange.input.ts b/libs/api/domains/regulations-admin/src/lib/graphql/dto/updateDraftRegulationChange.input.ts
index c52fdccdcac5..7f017faa0845 100644
--- a/libs/api/domains/regulations-admin/src/lib/graphql/dto/updateDraftRegulationChange.input.ts
+++ b/libs/api/domains/regulations-admin/src/lib/graphql/dto/updateDraftRegulationChange.input.ts
@@ -8,6 +8,9 @@ class UpdateChangeAppendixInput {
 
   @Field(() => String, { nullable: true })
   text!: HTMLText
+
+  @Field(() => String, { nullable: true })
+  diff?: HTMLText
 }
 
 @InputType()
diff --git a/libs/api/domains/regulations-admin/src/lib/graphql/models/draftRegulationChange.model.ts b/libs/api/domains/regulations-admin/src/lib/graphql/models/draftRegulationChange.model.ts
index 3d1f03e2163c..1f5e340f2b9c 100644
--- a/libs/api/domains/regulations-admin/src/lib/graphql/models/draftRegulationChange.model.ts
+++ b/libs/api/domains/regulations-admin/src/lib/graphql/models/draftRegulationChange.model.ts
@@ -8,6 +8,9 @@ export class ChangeAppendix {
 
   @Field(() => String, { nullable: true })
   text!: HTMLText
+
+  @Field(() => String, { nullable: true })
+  diff?: HTMLText
 }
 
 @ObjectType()
diff --git a/libs/portals/admin/regulations-admin/src/components/EditBasics.tsx b/libs/portals/admin/regulations-admin/src/components/EditBasics.tsx
index 6cf202cbdd87..304a1e004f20 100644
--- a/libs/portals/admin/regulations-admin/src/components/EditBasics.tsx
+++ b/libs/portals/admin/regulations-admin/src/components/EditBasics.tsx
@@ -27,6 +27,8 @@ import { RegulationDraftTypes } from '../types'
 import ConfirmModal from './ConfirmModal/ConfirmModal'
 import { ReferenceText } from './impacts/ReferenceText'
 import { DraftChangeForm, DraftImpactForm } from '../state/types'
+import { makeDraftAppendixForm } from '../state/makeFields'
+import { hasAnyChange } from '../utils/formatAmendingUtils'
 
 const updateText =
   'Ósamræmi er í texta stofnreglugerðar og breytingareglugerðar. Texti breytingareglugerðar þarf að samræmast breytingum sem gerðar hafa verið á stofnreglugerð, eigi breytingarnar að færast inn með réttum hætti.'
@@ -37,6 +39,7 @@ export const EditBasics = () => {
   const [editorKey, setEditorKey] = useState('initial')
   const [titleError, setTitleError] = useState<string | undefined>(undefined)
   const [hasUpdated, setHasUpdated] = useState<boolean>(false)
+  const [hasUpdatedAppendix, setHasUpdatedAppendix] = useState<boolean>(false)
   const [references, setReferences] = useState<DraftImpactForm[]>()
   const [isModalVisible, setIsModalVisible] = useState<boolean>(true)
   const [hasConfirmed, setHasConfirmed] = useState<boolean>(false)
@@ -45,8 +48,7 @@ export const EditBasics = () => {
   const { text, appendixes } = draft
   const { updateState } = actions
 
-  const startTextExpanded =
-    !text.value || appendixes.length === 0 || !!text.error
+  const startTextExpanded = true
 
   const regType =
     draft.type.value &&
@@ -118,6 +120,45 @@ export const EditBasics = () => {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [draft.impacts])
 
+  useEffect(() => {
+    if (!hasUpdatedAppendix && hasUpdated) {
+      updateAppendixes()
+      setHasUpdatedAppendix(true)
+    }
+  }, [hasUpdated, hasUpdatedAppendix])
+
+  const updateAppendixes = () => {
+    // FORMAT AMENDING REGULATION APPENDIXES
+    const impactArray = Object.values(draft.impacts).flat()
+    const amendingArray = impactArray.filter(
+      (item) => item.type === 'amend',
+    ) as DraftChangeForm[]
+
+    if (appendixes?.length > 0) {
+      appendixes.splice(0, appendixes.length)
+    }
+
+    amendingArray.map((item) => {
+      item.appendixes.map((apx, idx) => {
+        if (apx.diff?.value && hasAnyChange(apx.diff.value)) {
+          const defaultTitle = apx.title.value ?? `Viðauki ${idx + 1}`
+          const defaultText = apx.text.value
+          if (
+            appendixes?.length === 0 ||
+            !appendixes.some((ap) => ap.text.value === defaultText)
+          ) {
+            appendixes.push(
+              makeDraftAppendixForm(
+                { title: defaultTitle, text: defaultText },
+                String(appendixes.length),
+              ),
+            )
+          }
+        }
+      })
+    })
+  }
+
   const updateEditorText = () => {
     const additions = formatAmendingBodyWithArticlePrefix(draft.impacts)
 
@@ -125,6 +166,7 @@ export const EditBasics = () => {
     updateState('title', formatAmendingRegTitle(draft))
     const additionString = additions.join('') as HTMLText
     updateState('text', additionString)
+
     setHasUpdated(true)
   }
 
@@ -228,7 +270,7 @@ export const EditBasics = () => {
                     name: (references[0].name as RegName) ?? '',
                     appendixes: references[0].appendixes.map((apx) => ({
                       title: apx.title.value,
-                      text: apx.text.value,
+                      text: apx.diff?.value,
                     })),
                   } as Regulation
                 }
diff --git a/libs/portals/admin/regulations-admin/src/components/impacts/EditChange.tsx b/libs/portals/admin/regulations-admin/src/components/impacts/EditChange.tsx
index 80e0109d7139..5610b4fbccc2 100644
--- a/libs/portals/admin/regulations-admin/src/components/impacts/EditChange.tsx
+++ b/libs/portals/admin/regulations-admin/src/components/impacts/EditChange.tsx
@@ -221,12 +221,32 @@ export const EditChange = (props: EditChangeProp) => {
     validateImpact(activeChange)
   }, [activeChange])
 
-  const getDiffHtml = () => {
-    const emptyHTML = '' as HTMLText
-    const prev = previousRegulation?.text || emptyHTML
-    const current = activeChange.text.value || emptyHTML
+  const emptyHTML = '' as HTMLText
+  const getDiffHtml = (previous?: HTMLText, current?: HTMLText) => {
+    const prev = previous || previousRegulation?.text || emptyHTML
+    const curr = current || activeChange.text.value || emptyHTML
 
-    return getDiff(dirtyClean(prev), dirtyClean(current)).diff || emptyHTML
+    return getDiff(dirtyClean(prev), dirtyClean(curr)).diff || emptyHTML
+  }
+
+  const getAppendixDiffHtml = (i: number) => {
+    const previous = previousRegulation?.appendixes[i]?.text || emptyHTML
+    const current = activeChange?.appendixes[i]?.text.value || emptyHTML
+
+    const diff = getDiff(dirtyClean(previous), dirtyClean(current)).diff
+
+    if (!previousRegulation?.appendixes[i]) {
+      // If the appendix is new
+      return `<div data-diff="new">${diff}</div>` as HTMLText
+    }
+
+    if (diff) {
+      // If the appendix has changes
+      return diff
+    } else {
+      // If the appendix has no changes
+      return undefined
+    }
   }
 
   const saveChange = async () => {
@@ -239,9 +259,10 @@ export const EditChange = (props: EditChangeProp) => {
             title: activeChange.title.value,
             text: activeChange.text.value,
             diff: getDiffHtml(),
-            appendixes: activeChange.appendixes.map((apx) => ({
+            appendixes: activeChange.appendixes.map((apx, i) => ({
               title: apx.title.value,
               text: apx.text.value,
+              diff: getAppendixDiffHtml(i),
             })),
             date: toISODate(activeChange.date.value),
           },
@@ -264,9 +285,10 @@ export const EditChange = (props: EditChangeProp) => {
             title: activeChange.title.value,
             text: activeChange.text.value,
             diff: getDiffHtml(),
-            appendixes: activeChange.appendixes.map((apx) => ({
+            appendixes: activeChange.appendixes.map((apx, i) => ({
               title: apx.title.value,
               text: apx.text.value,
+              diff: getAppendixDiffHtml(i),
             })),
             date: toISODate(activeChange.date.value),
           },
diff --git a/libs/portals/admin/regulations-admin/src/components/impacts/ReferenceText.tsx b/libs/portals/admin/regulations-admin/src/components/impacts/ReferenceText.tsx
index 911dde865d50..15adaff457e9 100644
--- a/libs/portals/admin/regulations-admin/src/components/impacts/ReferenceText.tsx
+++ b/libs/portals/admin/regulations-admin/src/components/impacts/ReferenceText.tsx
@@ -87,7 +87,10 @@ export const ReferenceText = (props: ReferenceTextProps) => {
           {appendixes.map(({ title, text }, i) => (
             <div className={s.referenceTextAppendix} key={i}>
               <h2 className={s.referenceTextAppendixTitle}>{title}</h2>
-              <HTMLDump className={ed.classes.editor} html={text as HTMLText} />
+              <HTMLDump
+                className={cn(ed.classes.editor, s.diff)}
+                html={text as HTMLText}
+              />
             </div>
           ))}
 
diff --git a/libs/portals/admin/regulations-admin/src/state/makeFields.ts b/libs/portals/admin/regulations-admin/src/state/makeFields.ts
index 08893a853de9..c4c02a5a9b32 100644
--- a/libs/portals/admin/regulations-admin/src/state/makeFields.ts
+++ b/libs/portals/admin/regulations-admin/src/state/makeFields.ts
@@ -153,11 +153,12 @@ export const makeDraftChangeForm = (
 // ---------------------------------------------------------------------------
 
 export const makeDraftAppendixForm = (
-  appendix: Appendix,
+  appendix: Appendix & { diff?: HTMLText },
   key: string,
 ): AppendixDraftForm => ({
   title: fText(appendix.title, true),
   text: fHtml(appendix.text, true),
+  diff: appendix.diff ? fHtml(appendix.diff) : undefined,
   key,
 })
 
diff --git a/libs/portals/admin/regulations-admin/src/state/types.ts b/libs/portals/admin/regulations-admin/src/state/types.ts
index 09256108c289..f04b7dc2cb26 100644
--- a/libs/portals/admin/regulations-admin/src/state/types.ts
+++ b/libs/portals/admin/regulations-admin/src/state/types.ts
@@ -47,6 +47,7 @@ export type AppendixDraftForm = {
   title: DraftField<PlainText, 'text'>
   text: HtmlDraftField
 
+  diff?: HtmlDraftField
   /**
    * Appendixes may be revoked by `RegulationChange`s.
    *
diff --git a/libs/portals/admin/regulations-admin/src/utils/formatAmendingRegulation.ts b/libs/portals/admin/regulations-admin/src/utils/formatAmendingRegulation.ts
index 884527fd26c2..6c16e129d746 100644
--- a/libs/portals/admin/regulations-admin/src/utils/formatAmendingRegulation.ts
+++ b/libs/portals/admin/regulations-admin/src/utils/formatAmendingRegulation.ts
@@ -1,5 +1,9 @@
 import { asDiv, HTMLText } from '@island.is/regulations'
-import { GroupedDraftImpactForms, RegDraftForm } from '../state/types'
+import {
+  AppendixDraftForm,
+  GroupedDraftImpactForms,
+  RegDraftForm,
+} from '../state/types'
 import format from 'date-fns/format'
 import is from 'date-fns/locale/is'
 import compact from 'lodash/compact'
@@ -10,8 +14,10 @@ import {
   extractArticleTitleDisplay,
   getTextWithSpaces,
   groupElementsByArticleTitleFromDiv,
+  hasAnyChange,
   isGildisTaka,
   removeRegPrefix,
+  updateAppendixWording,
 } from './formatAmendingUtils'
 import { getDeletionOrAddition } from './getDeletionOrAddition'
 
@@ -173,6 +179,7 @@ export const formatAmendingRegBody = (
   repeal?: boolean,
   diff?: HTMLText | string | undefined,
   regTitle?: string,
+  appendixes?: AppendixDraftForm[],
 ) => {
   const regName = removeRegNamePrefix(name)
   if (repeal) {
@@ -409,6 +416,34 @@ export const formatAmendingRegBody = (
     }
   })
 
+  appendixes?.map((apx, idx) => {
+    if (apx.diff?.value) {
+      const defaultTitle = apx.title.value ?? `Viðauki ${idx + 1}`
+
+      const regNameAddition =
+        regName && regName !== 'self'
+          ? `reglugerð nr. ${regName}`.replace(/\.$/, '')
+          : 'reglugerðina'
+      const regNameChange =
+        regName && regName !== 'self'
+          ? `, reglugerðar nr. ${regName}`.replace(/\.$/, '')
+          : ''
+
+      const testAddTitle = `Við ${regNameAddition} bætist nýr viðauki, ${defaultTitle} sem ${
+        /fylgiskjal/i.test(defaultTitle) ? 'birt' : 'birtur'
+      } er með reglugerð þessari.`
+      const testChangeTitle = `Eftirfarandi breytingar eru gerðar á ${updateAppendixWording(
+        defaultTitle,
+      )}${regNameChange}:`
+
+      if (apx.diff?.value.includes('<div data-diff="new">')) {
+        additionArray.push([`<p>${testAddTitle}</p>` as HTMLText])
+      } else if (hasAnyChange(apx.diff?.value)) {
+        additionArray.push([`<p>${testChangeTitle}</p><p>[]</p>` as HTMLText])
+      }
+    }
+  })
+
   return additionArray.flat()
 }
 
@@ -426,6 +461,7 @@ export const formatAmendingBodyWithArticlePrefix = (
             item.type === 'repeal',
             item.type === 'amend' ? item.diff?.value : undefined,
             item.regTitle,
+            item.type === 'amend' ? item.appendixes : undefined,
           ),
           date: item.date.value,
         }
diff --git a/libs/portals/admin/regulations-admin/src/utils/formatAmendingUtils.ts b/libs/portals/admin/regulations-admin/src/utils/formatAmendingUtils.ts
index 007246a3332a..3c788317fec8 100644
--- a/libs/portals/admin/regulations-admin/src/utils/formatAmendingUtils.ts
+++ b/libs/portals/admin/regulations-admin/src/utils/formatAmendingUtils.ts
@@ -1,5 +1,5 @@
 import isSameDay from 'date-fns/isSameDay'
-import { HTMLText } from '@island.is/regulations'
+import { HTMLText, asDiv } from '@island.is/regulations'
 
 export const groupElementsByArticleTitleFromDiv = (
   div: HTMLDivElement,
@@ -87,3 +87,30 @@ export const allSameDay = (objects: AdditionObject[]): boolean => {
 
   return validObjects.every((obj) => isSameDay(obj.date!, firstDate))
 }
+
+export const hasAnyChange = (diff: string) => {
+  const testElement = asDiv(diff)
+  const hasDeletion = !!testElement.querySelector('del')
+  const hasInsert = !!testElement.querySelector('ins')
+
+  return hasDeletion || hasInsert
+}
+
+export const updateAppendixWording = (input: string): string => {
+  return input.replace(/fylgiskjal|viðauki/gi, (match) => {
+    if (match[0] === match[0].toUpperCase()) {
+      if (match.toLowerCase() === 'fylgiskjal') {
+        return 'Fylgiskjali'
+      } else if (match.toLowerCase() === 'viðauki') {
+        return 'Viðauka'
+      }
+    } else {
+      if (match.toLowerCase() === 'fylgiskjal') {
+        return 'fylgiskjali'
+      } else if (match.toLowerCase() === 'viðauki') {
+        return 'viðauka'
+      }
+    }
+    return match
+  })
+}