diff --git a/packages/taler-util/src/payto.ts b/packages/taler-util/src/payto.ts
index 1ac081a76..dd35b44be 100644
--- a/packages/taler-util/src/payto.ts
+++ b/packages/taler-util/src/payto.ts
@@ -55,6 +55,66 @@ export interface PaytoUriBitcoin extends PaytoUriGeneric {
 
 const paytoPfx = "payto://";
 
+export function buildPayto(
+  type: "iban",
+  iban: string,
+  bic: string | undefined,
+): PaytoUriIBAN;
+export function buildPayto(
+  type: "bitcoin",
+  address: string,
+  reserve: string | undefined,
+): PaytoUriBitcoin;
+export function buildPayto(
+  type: "x-taler-bank",
+  host: string,
+  account: string,
+): PaytoUriTalerBank;
+export function buildPayto(
+  type: "iban" | "bitcoin" | "x-taler-bank",
+  first: string,
+  second?: string,
+): PaytoUriGeneric {
+  switch (type) {
+    case "bitcoin": {
+      const result: PaytoUriBitcoin = {
+        isKnown: true,
+        targetType: "bitcoin",
+        targetPath: first,
+        params: {},
+        segwitAddrs: !second ? [] : generateFakeSegwitAddress(second, first),
+      };
+      return result;
+    }
+    case "iban": {
+      const result: PaytoUriIBAN = {
+        isKnown: true,
+        targetType: "iban",
+        iban: first,
+        params: {},
+        targetPath: !second ? first : `${second}/${first}`,
+      };
+      return result;
+    }
+    case "x-taler-bank": {
+      if (!second) throw Error("missing account for payto://x-taler-bank");
+      const result: PaytoUriTalerBank = {
+        isKnown: true,
+        targetType: "x-taler-bank",
+        host: first,
+        account: second,
+        params: {},
+        targetPath: `${first}/${second}`,
+      };
+      return result;
+    }
+    default: {
+      const unknownType: never = type;
+      throw Error(`unknown payto:// type ${unknownType}`);
+    }
+  }
+}
+
 /**
  * Add query parameters to a payto URI
  */
@@ -84,8 +144,8 @@ export function stringifyPaytoUri(p: PaytoUri): string {
   const url = new URL(`${paytoPfx}${p.targetType}/${p.targetPath}`);
   const paramList = !p.params ? [] : Object.entries(p.params);
   paramList.forEach(([key, value]) => {
-    url.searchParams.set(key, value)
-  })
+    url.searchParams.set(key, value);
+  });
   return url.href;
 }