mEdtPaymentCreditNumber.addTextChangedListener(new FourDigitCardFormatWatcher());

   public static class FourDigitCardFormatWatcher implements TextWatcher {

        private static final char space = ' ';

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
            // Remove spacing char
            if (s.length() > 0 && (s.length() % 5) == 0) {
                final char c = s.charAt(s.length() - 1);
                if (space == c) {
                    s.delete(s.length() - 1, s.length());
                }
            }
            // Insert char where needed.
            if (s.length() > 0 && (s.length() % 5) == 0) {
                char c = s.charAt(s.length() - 1);
                // Only if its a digit where there should be a space we insert a space
                if (Character.isDigit(c) && TextUtils.split(s.toString(), String.valueOf(space)).length <= 3) {
                    s.insert(s.length() - 1, String.valueOf(space));
                }
            }
        }
    }